Setting
Subsea
Underwater work location including seabed and submerged infrastructure.
Newest 100 Documents
All 279 in search- 202628 Apr
Diver entanglement – umbilical caught around an anode
A diver’s umbilical snagged on a conductor-shaft anode at 18 msw after tidal current pushed it towards the structure. Slack allowed in-water decompression to continue while a stand-by diver freed the line. Planned diving time was not exceeded. The flash highlights attention to local environmental conditions and situational awareness.
- 202628 Apr
Diver entanglement – uncontrolled equipment in the water column
During shallow-water welding, a diver’s bail-out regulator became entangled in a rope supporting a rubber mat and welding rods. Swell moved the suspended items uncontrollably. A stand-by diver freed him within the planned diving time. The flash highlights loose-rope avoidance, tool positioning and possible use of lockable carabiners.
- 202631 Mar
Source control planning and procedures information paper
This information paper sets out regulatory expectations for offshore loss-of-well-control preparedness across environment plans, well operations management plans and safety cases. It covers capping-stack selection and deployment, relief-well design and dynamic kill analysis, plume modelling, subsea dispersant supply, water-column monitoring, response-time modelling, coordinated operations and readiness exercises.
- 2026Mar
PON1 Guidance for Reporting Oil and Offshore Chemical Releases
Guidance sets out PON1 notification requirements for oil and offshore chemical releases during offshore oil and gas activities. It distinguishes releases from intentional discharges, specifies reporting responsibilities, timeframes and portal submission, and explains quantity determination and ongoing updates. Appendices address subsea systems, drainage, produced-water caissons, vessels, flaring and excessive powder venting.
- 2026Mar
Production PINCs
Numbered regulatory inspection questions address production safety systems, well barriers and casing-pressure diagnostics. Checks cover shutdown valve operation, gas and fire detection calibration, firewater pumps, pressure relief and protective devices on process equipment. Conditional approval requirements and specified testing intervals support inspection of production facilities and subsea components.
- 202622 Jan
Dropped GRP cover during subsea lifting
A GRP manifold cover detached during subsea relocation and dropped approximately 7 m, without injury or damage to the manifold or bottom structure. Findings identified excessive loading during a crane mode transition and erroneous lifting-rod calculations. Revised lift planning removed the mode switch and used deployment lifting points; keeping divers clear prevented potential serious injury.
- 2026Jan
D-PINCs (Operators Version - Jan 2026) — Drilling
A regulatory checklist for oil and gas drilling, linking numbered compliance questions to statutory authorities and enforcement actions. It addresses approvals, diverter configuration and testing, casing installation, cement placement, drilling-fluid management and monitoring. Further checks cover ventilation, gas detection, ignition prevention and retention of drilling and test records.
- 2026Jan
Well Operations
An inspection guide presenting compliance questions for well operations under Subpart G, with regulatory authorities and enforcement codes. It covers casing and liner integrity, surface and subsea blowout preventer configuration, pressure and function testing, maintenance and records, alongside specific requirements for coiled tubing and snubbing systems.
- 202518 Dec
BSEE: Anchor-handling causes damage to subsea equipment and triggers gas release
An anchor wire snagged a subsea well during recovery by a dive support vessel, subsequently detaching an annulus valve and releasing gas. The flash summarises BSEE findings on inadequate planning, coordination and emergency preparation, with recommendations for consideration covering readiness checks, change management, communication and current-aware anchor-handling plans.
- 202530 Sep
BSEE Safety Alert 508 -Review anchor-handling plans now Incident damages subsea equipment triggers gas release
A diver support vessel recovering bow anchors snagged a subsea well with an anchor wire. Attempts to free it detached the annulus valve, releasing gas. The alert identifies deficient planning, contractor coordination and emergency readiness, and recommends that operators and contractors consider stronger pre-mobilisation checks, SIMOPS arrangements and anchor-handling plans.
- 202514 Aug
Brazil: diver permanently disabled after decompression illness
A Brazilian diver suffered permanent disability following decompression illness after underwater inspection and maintenance at 26 m. The flash describes a malfunctioning hyperbaric chamber, delayed treatment elsewhere, and deficiencies in emergency planning, transport and communication. It highlights related IMCA guidance on therapeutic deck decompression chamber operations.
- 202531 Jul
Diver sustains laceration to right hand
A diver retrieving tooling during air/nitrox diving at 18 m suffered a deep right-thumb laceration when vessel movement parted a weak link and drew his hand towards a snatch block. The flash describes downline slack, hand positioning, full recovery, and changes to the downline arrangement and tool bag to reduce line-of-fire exposure.
- 202512 Jun
Design notification guidance note
Explains design notification requirements for new or significantly altered production facilities and new greenhouse gas facilities. Covers notification triggers, design options, major accident risks, pipeline materials, decommissioning and site conditions. Clarifies independent validation, subsequent safety-case demonstrations and NOPSEMA’s assessment process, which produces written comments rather than acceptance.
- 20253 Apr
Incidents occurring during decommissioning
This safety flash compiles decommissioning incidents involving offshore structures, lifting and diving work. Cases include falling loads, damaged rigging, structural collapse, chemical exposure and underwater burning. It summarises breaches of selected life-saving rules and records a riser recovery incident in which personnel remained clear of the lifting area and escaped injury.
- 20256 Mar
Diver lifted off seabed
A diver’s umbilical snagged on another bell’s clump weight, lifting the diver approximately 4–5 m above the seabed during adjustment. Services remained intact. The flash describes stopping the operation and clearing the umbilical, and recommends second-diver or ROV monitoring when divers pass close to objects being lifted.
- 20256 Mar
Divers helmet struck and damaged subsea by crane hook
A crane hook slipped from a pipe handling frame during subsea spool tie-in work in poor visibility, striking and irreparably damaging a diver’s reclaim helmet without injury. The flash identifies insufficient pennant length and discusses safe separation, position monitoring, reinforced communication, rigging inspections and revised task hazard analysis.
- 202520 Feb
NOPSEMA – Fauna entanglement
An IMCA safety flash relays a NOPSEMA alert about a shark trapped in a rope loop on an electrical flying lead and freed using an ROV knife without additional harm. It discusses marine fauna interactions with subsea equipment and measures to consider, including installation-aid removal, alternative designs and protective guards.
- 2024Dec
Environmental Compliance
An environmental compliance checklist links inspection questions to regulatory authorities and enforcement actions. It covers marine debris, air and water quality, archaeological resources, artificial reefs, marine ecology, protected species and seafloor clearance, checking compliance with lease conditions, approved plans, permits and bureau instructions.
- 202412 Nov
Diver exposed to unplanned release of production gas
A saturation diver removing a blind stab from a subsea skid was pushed backwards by released production gas but remained unharmed. The flash identifies unverified isolation, deviation from procedures, inadequate review of task risks and unused ROV tooling. It highlights change management, procedural hold points and reinforcement of stop-work authority.
- 20243 Oct
Fauna entanglement
An environmental alert describes a shark caught in a rope loop on a subsea electrical flying lead and released using an ROV knife without additional harm. It discusses evaluating fauna interaction risks, considering installation-aid removal and safer designs, guarding injury mechanisms, verifying controls and meeting protected-species incident reporting requirements.
- 20243 Sep
Near miss: lift bag released unintentionally from crane hook
A lift bag detached from a crane hook at the splash-zone during a saturation dive and floated near a vessel operating in DP mode. Incorrect folding and attachment allowed buoyancy to defeat the self-locking latch. No harm occurred. The flash recommends risk assessment, rigging checks and a tool basket.
- 2024Aug
CHIRP Superyacht FEEDBACK 7 (August 2024)
Six superyacht reports examine tender lifting-point failure, fouled anchors near a lee shore, an open shell door, a fall during window cleaning and unsafe diving arrangements. Commentary emphasises thorough risk assessment, properly completed work permits, reliable equipment, crew communication and isolation during underwater maintenance.
- 202424 Jul
Uncontrolled release of lower marine riser package
Following unlatching from the BOP ahead of pending weather, an uncontrolled riser-string release left the lower marine riser package on the seabed. Five droop hoses initially connected the upright string to the rig, then failed, allowing it to fall away from infrastructure. No personnel injuries or subsea asset damage were reported.
- 202416 Jul
Loss of pressure to diver’s primary air supply
A diver was recovered safely after primary air supply pressure fell. Surface testing traced regulator sticking to dried lubricant restricting the sensing assembly, particularly during light breathing. The flash discusses supervisory intervention, insufficient internal servicing, regulator rotation and increased six-monthly maintenance, testing and cleaning.
- 20242 Jul
ROV dropped to seabed
An ROV fell to the seabed after recovery-system latching problems and umbilical separation. Cold, dirty grease slowed the latch, while the operator could not see the locked-position indicator. The flash identifies maintenance, procedure and supervision shortcomings and describes cleaning, functional verification and renewed procedural assurance.
- 202427 Jun
Safety warning issued following contact between a diving support boat and a recreational diver with loss of 1 life
This bulletin examines a fatal recreational diving accident in Scapa Flow, almost certainly involving Karin’s rotating propeller. It highlights an unseen delayed surface marker buoy during drift decompression, dedicated lookouts, safe vessel standoff and coordination between boats. Divers should hold buoy lines rather than attach them to themselves.
- 20243 Jun
Diver’s umbilical trapped during a pipeline flooding operation
A saturation diver’s umbilical became trapped between pipelines when a newly laid line shifted during flooding, interrupting breathing gas. Another diver supplied pneumo gas and helped free the umbilical. The flash examines pipeline configuration, tidal current and umbilical routing, emphasising assessment of existing conditions and management of changing variables.
- 202427 Mar
Loss of heading control on an FPU during diving operations
A floating production unit lost heading control during diving operations when a steering pump failed to start automatically during greasing. Only one thruster was available. Divers were recovered safely. The flash examines maintenance coordination, work permits, risk assessment and communication, and calls for changes to the company SIMOPS matrix.
- 202410 Jan
Considerations for five-year environment plan revisions
This information paper advises petroleum titleholders preparing five-year environment plan revisions for long-term offshore activities. It addresses legislative changes, activity scope, subsea maintenance and decommissioning, spill prevention and response, emissions reduction, consultation and environmental monitoring. It explains expectations for demonstrating ALARP, acceptable impacts and measurable environmental performance.
- 20249 Jan
Divers lifted off seabed by Clump Weight
During subsea diving, taut wire recovery pulled two divers from the seabed to 18 m above their maximum excursion depth, risking pressure-induced injuries. Both reported well after transfer and tests. The flash identifies communication failures and missing lift planning, and describes revised diver-clearance requirements, repeat-back instructions and stop-work measures.
- 202319 Dec
NOPSEMA and OIR Research Strategy 2024-2027
This strategy identifies collaborative research priorities for environmental management of offshore energy projects. It addresses cumulative impacts, underwater noise, fauna detection, emissions, decommissioning and geological carbon storage. Priorities include seabed remediation, standardised bird monitoring and renewable-energy mitigation research, while distinguishing the regulator’s research end-user role from conducting or funding research.
- 202327 Nov
Case study: Saturation diver fatality due to hydrogen sulphide
This safety flash summarises a historical saturation-diving fatality during inspection of a leaking sour-crude pipeline in the Bombay High oilfield. Hydrogen sulphide in the bell caused collapse; the diver subsequently drowned. It discusses possible gas-entry routes, absent gas detection, bell-to-bell rescue and the potential use of ROVs for surveys.
- 202328 Sep
Safety Alert - Pipeline Loss of Containment
A gas export pipeline tie-in spool flange failed after severe corrosion of carbon steel lacking the specified corrosion-resistant cladding. The alert examines material traceability and quality-control failures, misinterpreted inline inspection data and incorrect defect location reporting. Lessons address preserved identification, consideration of positive material identification and diverse integrity inspection measures.
- 20233 Aug
Unexpected descent and ascent of mattress lifting frame
A mattress handling frame descended and abruptly ascended near divers during crane operations in active heave compensation mode. No injuries or damage occurred. The flash identifies controller-lock software interactions, obsolete operating manuals and inadequate familiarisation, with actions addressing revision control, operator briefings and protection of the controller-lock button.
- 202324 Jul
Restricted air supply to diver
A diver recovery drill was aborted after uneven basket recovery strained and kinked a standby diver’s umbilical, restricting his main air supply and prompting bailout. Both divers reached the surface safely. The flash identifies communication, planning and supervision shortcomings, and emphasises umbilical management and incorporating incident learning into procedures.
- 202316 May
Differential pressure: Dummy choke ejected close to divers
A dummy choke insert was expelled by differential pressure during replacement work near two divers, who remained unharmed. The flash examines absent local venting, misunderstood pressure readings and unclear release expectations. It recommends explicit procedures and risk assessments, isolation training, confirmation of an open local vent and clarification of questionable instructions.
- 202313 Mar
Lift bag near miss
A lift bag escaped its intended rigging during spool over-boarding and was arrested by contingency rigging. The flash examines inappropriate attachment, undocumented rigging changes, unclear diver communications and task-generic procedures. Lessons emphasise single-person rigging accountability, task-specific instructions, reduced multitasking and thorough communication during personnel changes.
- 20237 Mar
Investigation of Subsea Leak Identifies the Use of Materials Susceptible to Hydrogen Embrittlement (update)
A subsea jumper leak released approximately 479 barrels of oil into the Gulf of Mexico. Investigation attributed fractured Inconel 718 flange studs to hydrogen embrittlement and identified procurement, quality assurance and change-management gaps. The alert recommends operators consider metallurgical evaluation, fastener torque documentation and improved subsea leak alarm monitoring.
- 202327 Feb
Near miss: Foreign body in diver’s helmet, resulting in fall of gas pressure
A diver at 18 m experienced reduced breathing gas pressure. Bailout gas did not resolve the problem, but free flow restored suitable pressure. A plastic shard from a broken cleaning pot was found in the helmet regulator. The flash highlights pre-dive checks, cleanliness and the member’s introduction of spray bottles.
- 202311 Jan
Lost ROV incident
An ROV became trapped in a platform jacket during routine inspection in strong tidal current. Tether damage interrupted power and telemetry; subsequent recovery failed and the vehicle was lost. The flash identifies inadequate recovery procedures, understaffing and premature beacon battery exhaustion, and records procedural revisions and a current display added to the pilot interface.
- 202311 Jan
Umbilical management – near miss
A diver’s umbilical became trapped when a pipeline rolled during crane-assisted removal of sleeper supports beneath a repair spool. The diver freed it and was unharmed. The flash identifies missing removal procedures, unrecognised umbilical hazards and absent change management, recommending a removal procedure and crew review.
- 202214 Nov
MUX Cables and Hotline Hose Damage results in BOP Control Pods Losing Power and Communications
A subsea blowout preventer experienced partial communications loss while latched to a well. Excessive tension during harsh weather and extreme heave damaged the hotline hose and yellow and blue pod multiplexed communication cables. BOP control and operability remained available through the Acoustic Pod and subsea ROV panel.
- 20221 Nov
Hydraulic Oil Leak to Sea from Downline Fitting
During decommissioning with a diamond wire saw, 100 litres of hydraulic oil escaped to sea through a slack BSP downline fitting. Tightness checks had been omitted because the checklist prompted only visual inspection. Actions included physical tightness checks, checklist revision, additional fitting supports and removal of the hydraulic hose bight following feasibility review.
- 20225 Sep
LTI: Diver suffered crush injury to finger
A diver injured his ring finger positioning a subsea tree panel during decommissioning when vessel heave moved the crane-supported load. The flash recommends hands-off lifting wherever possible, reviewing risk assessments where this is not possible or advisable, and providing guidance for choosing between crane and lift-bag methods.
- 202231 May
Near miss: grinder disc rotation set up in the wrong direction
A diver’s pre-operational checks identified reversed disc rotation on a GR29 underwater grinder modified for left-handed cutting, creating a risk of the cutting disc lock nut coming off. Work stopped and the tool was quarantined. The flash describes changing handle and guard orientation while retaining the original rotation direction.
- 202221 Apr
COBRA System – Hose coupling cross threaded
A diving safety flash describes leakage from a COBRA hose coupling that was cross-threaded and subsequently pulled free during helmet removal in the bell. It examines restricted access and reliance on a green pressure indicator, highlighting coupling alignment awareness, visible-thread checks and a requested supplier review of the coupling mechanism.
- 202221 Apr
Diver experienced an air flow restriction
A surface-supplied diver experienced restricted air flow at 23msw and the dive was aborted without injury. Investigation identified a needle valve that failed to open properly, with possible overtightening linked to premature equipment fatigue. Actions included valve replacement, revised pre-dive checks and operating procedures, and a team emergency debrief.
- 202221 Apr
Subsea transponder wire parted
A positioning transponder’s tripod wire parted during vessel repositioning. The 4 mm wire failed approximately 1 m from the lifting eye, with corrosion and insufficient replacement identified. Divers and a crane recovered the tripod. Actions included performance testing, visual checks before launch and during recovery, and six-monthly wire replacement.
- 202222 Mar
MAIB: Unexploded ordnance – subsea explosion causes injury and damage
This safety flash summarises a seabed bomb explosion during crab-pot hauling by Galwad-Y-Mor in the North Sea. Five crew members suffered significant injuries, while the vessel sustained major damage and flooding. It highlights effective distress communication, evacuation, rescue and casualty triage, alongside the hull’s resistance to the blast.
- 202228 Jan
Incorrect as-built drawing configuration
Divers investigating leaks at a subsea manifold followed approved procedures based on incorrect client information. Fault-finding revealed a different jumper configuration, leaving only one unproven barrier during intervention. Work stopped pending confirmation of safety; the client investigated without identifying how the error arose, and amended drawings were formally approved.
- 202228 Jan
Near miss: Diver's umbilical drawn beneath a load
A diver’s umbilical was drawn beneath a GRP cover by suction during rigging hook-up. Vessel heave unexpectedly lifted the cover while crane active heave compensation was in use. The soft seabed prevented damage, with no service interruption or injuries. The risk assessment had not identified this umbilical movement hazard.
- 202220 Jan
Subsea explosion resulting in damage to crab potting vessel Galwad-Y-Mor and injuries to crew
Investigation of a seabed bomb explosion during crab-pot recovery by Galwad-Y-Mor, causing vessel damage, flooding and significant crew injuries. The report assesses potting-gear disturbance of likely wartime ordnance, fragment examination and explosive traces, alongside watertight subdivision, crew preparedness, rescue and casualty triage.
- 20219 Dec
Failure of 64mm polyester rope in subsea mooring operations
A 64mm polyester rope parted while subsea equipment was being lowered, following overload from unsynchronised crane and deployment-winch movements. Nobody was injured, but equipment was damaged. The flash examines missed operator concerns, simultaneous operations and unused stop-work authority, and describes tension indication, improved coordination and retraining in existing procedures.
- 20212 Dec
UHMPE pull-in rope damaged during mooring connection to buoy
During a subsea buoy mooring connection, a UHMPE pull-in rope escaped ROV control, damaging its arm, while the rope’s other end entered a propeller and was cut. The flash identifies current, propulsion wash, insufficient catenary monitoring and underestimated deck friction, and records amendments to the installation procedure and task plan.
- 202119 Nov
Diver finger injury from Lionfish fin ray
A diver’s right thumb was punctured through a glove while trying to push away a lionfish. Recovery by diving bell enabled medical treatment. The flash describes glove suitability review, refresher training and risk assessment updates, alongside dive briefings, supervisor video monitoring and increased buddy watching for venomous fish.
- 202128 Oct
Unexpected movement of conductor during diver dredging operations
During diver dredging before conductor cutting, a conductor toppled at a severance point, leaving an umbilical spanning between conductors. Crane restraint and vessel manoeuvring enabled release without injury or damage. The flash identifies incomplete task information and recommends conductor restraint, data verification, revised risk assessment and improved change management.
- 202119 Aug
Dropped object – unexpected release of spool
A spool fell to the seabed during relocation using a vessel crane and recertified lifting yoke. Unretracted stop knobs imposed unplanned forces, causing yoke failure. Findings highlight incomplete procedures, limited tooling expertise and misunderstood communications. Actions address tooling design, contractor competence, procedure interfaces and risk assessment.
- 202116 Jun
Dropped object – Door detached from TMS during dive
An ROV tether management system lost an aluminium door subsea after both bottom latches failed. The investigation identified an omitted check for secondary retention. The flash recommends checking fixings and reviewing dive checklists; DROPS cone analysis judged damage to nearby subsea assets very unlikely.
- 202123 Apr
Failed Seal on Subsea Safety Valve Causes Leak
A subsea safety-valve seal failure allowed hydrocarbons into hydraulic lines at a Gulf of Mexico production platform, releasing an estimated three to 50 barrels of hydraulic fluid and oil. The alert describes ROV sampling and leak isolation, and recommends considering hydraulic-system monitoring, alarm configuration and pressure management during leaks and platform evacuation.
- 202117 Mar
Offshore Pipeline Integrity Management (Issue 2)
Inspection guidance for assessing offshore hydrocarbon pipeline integrity management, compliance and performance. It addresses ageing and life extension, corrosion monitoring, pipeline and riser inspection, shutdown valve testing, pigging safeguards and emergency preparedness. Success criteria, sample inspection agendas and enforcement assessment guidance support examination of operators’ arrangements.
- 202121 Jan
Risk-Based Inspections of Subsea Leak Detection Technology Reveals Gaps in System Processes
BSEE reviews three subsea oil leaks and inspection findings showing weaknesses in leak-detection procedures and management processes. Operators and contractors are asked to consider clearer alarm response responsibilities, personnel training, system testing, configuration change control and ROV surveys. The alert emphasises investigating abnormal flow and learning from previous detection failures.
- 202026 Nov
Rigging failure – Clump weight dropped to seabed
A weather buoy’s 2.6-tonne clump weight dropped to the seabed after a chain link failed during deployment. The selected weight exceeded the design’s 450 kg allowance, and the chain was unsuitable for lifting. The flash recommends formal management of change, thorough lift planning and checks of rigging certification and suitability.
- 202023 Oct
Two deaths of military divers
Two military diving fatalities highlight different training failures. In the UK, a recovered diver’s cylinders were empty, prompting action over air endurance calculations and risk assessment. In New Zealand, investigators identified departures from training standards and covert breathing-apparatus mode switching. IMCA reiterates SCUBA’s limitations for offshore diving work.
- 202027 May
Blow Out Preventer (BOP) Drops to Seabed
This alert describes a blowout preventer falling to the seabed during deployment on marine riser. A subsea engineer inadvertently triggered the emergency disconnect sequence after mistaking its button for the wellhead connector valve override, separating the preventer from the lower marine riser package.
- 202031 Mar
Potential for diver injury operating a hand-held torque wrench
A diver’s use of a hand-held torque wrench on a subsea valve override was stopped by a technician. Sudden spring unwinding could have rotated the wrench into the diver. Ambiguous drawing warnings, incomplete procedures and unavailable installation instructions contributed to an unsafe assumption about tool suitability.
- 202031 Mar
Safety Alert 380 - Subsea Jumper Failure Leads to Leak
BSEE describes a subsea jumper failure involving internal corrosion and mechanical stress from pipeline and PLET movement. The October 2017 leak released an estimated 16,000 barrels of oil and remained undetected for over 24 hours. Recommendations address operator training, improved leak detection, corrosion mitigation and verification of pipeline design tolerances.
- 202017 Mar
Trencher angle inadvertently altered
Accidental joystick activation during offshore trenching raised the cutting wheel and reduced cutting depth, unnoticed during a shift handover and computer reboot. No equipment or permanent material damage occurred. The flash examines interface design and alarm tolerances, describing revised alarm settings, cessation of trenching during handovers and joystick deactivation.
- 201917 Dec
Diver trapped by anchor chain
A diver searching for a pipeline end manifold became trapped by a moving anchor chain after his umbilical caught beneath it. Another diver cut the umbilical and assisted his recovery. The flash identifies inadequate hazard identification, procedures not followed, late information and inappropriate vessel movements, and reinforces dive supervision.
- 201922 Nov
Main ROV lift wire umbilical and bullet parted
An inspection-class ROV and its tether management system fell to the seabed during recovery after the main lift connection parted. The flash examines a recently re-terminated, load-tested bullet connection, failed potting compound and high ambient temperatures, and records procedural changes addressing temperature limits, compound quantities and storage details.
- 201930 Sep
Near miss – Diving operations while alongside
A main engine started while a diver cleared bow-thruster debris in a dockyard; the bridge immediately shut it down and the diver escaped unhurt. The flash identifies failures in communication, permits, lockout/tagout and risk assessment, and recommends physical isolation and verified control-of-work arrangements before diving.
- 201923 Aug
Near miss: Diver’s umbilical trapped
During near-shore diving, an untended umbilical drifted against a seawater intake screen and became trapped when the automated bar started. Emergency stopping and manual reversal freed it; neither diver was injured. The flash identifies absent isolation and inadequate supervision, and records reviews of risk assessment, dive planning and permit requirements.
- 201913 Aug
Safety Alert 364 - Improper Riser Tension Leads to Subsea BOP Falling Off Wellhead Mandrel and Failure of Riser Adapter
A subsea BOP tilted during disconnection after insufficient riser tension overloaded its adapter, which subsequently failed, leaving the BOP on the seafloor. The well had been plugged and no pollution occurred. BSEE recommends considering calculated unlatching procedures, tension verification hold points, safe operating parameters and renewed risk assessments for well-to-well BOP moves.
- 201925 Jul
Mattress beam landed very close to divers
A mattress lifting beam was lowered dangerously close to saturation divers recovering concrete mattresses on the seabed. The flash identifies lost visual monitoring, poor visibility and failure to stop work. Follow-up checks addressed load separation, diver–crane communications, ROV monitoring, beam visibility aids and incident reporting.
- 201928 May
Partial pressure of oxygen (PPO₂) getting low in bell
During saturation diving at approximately 147 msw, oxygen partial pressure fell in a bell and the main oxygen bottle was subsequently found empty. The flash describes breathing-mix purging, BIBS use and recovery, followed by changes to oxygen make-up responsibilities, panel positioning, valve configuration and buffer-tank connections.
- 201913 May
Diver fatality during subsea lifting operations – update
This fatal diving incident update examines secondary life support activation after a trapped umbilical interrupted primary breathing gas during subsea spool relocation. Delayed completion of two-stage activation accelerated gas depletion. It reports equipment testing, refresher training and drills, and a decision to replace two-stage systems with single-stage activation.
- 201913 May
Weight dropped to the seabed narrowly missing diving bell
A winch wire trapped during preparation to launch an air-diving recovery system parted, dropping a 300 kg clump weight near a saturation diving bell and deployed divers. No injury or equipment damage occurred. The flash identifies missing pre-use checks, restricted drum visibility and loose-wrap design issues, recommending checks, visibility and drop-zone identification.
- 201925 Apr
Safety Alert 348 - Chemical Leak in Flying Lead Discovered by ROV
An ROV survey discovered a subsea paraffin-inhibitor leak from a hydraulic flying lead in the Gulf of Mexico. Outer-jacket damage compromised collapse resistance; loss of positive pressure resulted in collapse and tearing. BSEE recommends considering pressure-maintaining procedures, training, check valves, low-pressure alarms, inventory monitoring and regular ROV inspections.
- 201920 Mar
Near miss: Diver reports tight gas
A diver switched to bailout and returned to the submersible diving chamber after experiencing restricted gas supply. Internal valves secured during a delay had not been restored following completed checks. The flash highlights checklist timing, recording deviations and repeating valve checks before operations recommence, alongside formal review of habitual procedural changes.
- 2019
Proposed Well Control Rule Revisions Fact Sheet
Technical fact sheet summarising BSEE’s final revisions to well-control regulations for offshore oil and gas operations. It explains changes to real-time monitoring, independent verification, accumulator requirements and alternating BOP testing schedules, alongside retained provisions for double shear rams, maintenance, ROV intervention and source control.
- 201821 Dec
Umbilical termination failure and loss of ROV
An ROV and its TMS fell to the seabed during recovery after an umbilical termination detached. Examination identified poor termination workmanship and defects, alongside inadequate subcontractor skill and quality verification. Revised procedures require photographic evidence of assembly steps, with quality surveillance recommended for subcontractors. No personnel were injured.
- 20183 Sep
Diver fatality during subsea lifting operations
A diver died during spool relocation using lift bags at 172 metres seawater depth. Rigging caught the umbilical during uncontrolled spool ascent; subsequent trapping interrupted primary breathing gas. Secondary life support apparently functioned but did not prevent death. Pending investigation, interim recommendations address planning, supervision, documented instructions and stopping work when controls are inadequate.
- 20183 Sep
Two ‘accident advisories’ relating to diver fatalities
This safety flash summarises two Singapore WSHC advisories about diver fatalities. During underwater bracket installation, an adjacent concrete pile collapsed, trapping a diver against the seabed; he later died in hospital. A separate commercial diver disappeared during vessel hull cleaning, and his body was found two days later.
- 20183 Aug
High potential near miss: unplanned handling of unexploded ordnance
A high-potential near miss involved recovering and handling wartime munitions during subsea debris clearance. ROV operations continued after ammunition emerged, and crew handled recovered items before specialist advice prompted their return to the seabed. The flash identifies information, identification and management failures, calling for reinforced stop-work authority, change management and revised procedures.
- 201820 Jul
LTI: diver injured during water jetting operations
A saturation diver sustained a left-arm lost-time injury during subsea high-pressure water jetting when the gun failed and a component detached. The flash identifies loose locking bolts, inadequate nut retention, unavailable manuals and maintenance shortcomings. Actions included management of change, equipment-condition checks and a dive-team awareness briefing.
- 20184 Jun
Near miss: potential dropped objects on temporary buoy modules (TBMs)
Two near misses involved loose objects discovered on temporary buoyancy modules retrieved to deck during tension leg platform installation. One concerned unrecovered subsea lamps and missing subcontractor notification; the other involved an inadequately lashed retaining pin removed by an ROV. Actions addressed material recovery procedures and reinforced stop-work authority.
- 201811 Apr
Near miss: diver’s umbilical snagged by work basket during recovery to surface
A diver’s umbilical snagged on a tool basket being recovered by hydraulic crane, pulling him towards the diving basket roof before an effective all-stop intervention. The flash examines inadequate separation, umbilical slack and protruding pins, and describes improvements to communications, crane instructions and umbilical management.
- 201815 Mar
Collision between general cargo ship Saga Sky and barge Stema Barge II resulting in subsea power cables damage
Investigates the collision of Saga Sky and Stema Barge II off Kent during severe weather, with anchor dragging and severed interconnector cables. Examines outdated anchorage charts, cable burial and condition monitoring, ship handling and emergency towage availability. Recommendations address nautical information, heavy-weather procedures and emergency response capability.
- 20182 Mar
Loss of Containment (LoC) - Version 2 March 2018
Inspection guidance for assessing offshore oil and gas duty holders’ containment safeguards. It covers design, commissioning, operating limits, instrumented protection, relief, isolation, reinstatement and change management. Specialist sections address process hazards, FPSOs, tubing and hoses, alongside investigation, performance indicators, assurance and leadership.
- 201721 Dec
Load exceeding safe working load (SWL) leads to overstressed and damaged rigging
During pipeline decommissioning, a crane-suspended shear tool pulled downwards as its jaws closed, overloading and deforming the rigging. A nearby diver could have been harmed. The flash identifies planning and communication shortcomings and highlights tool placement, available slack, communicating rigging capacity and reviewing rigging drawings.
- 20177 Nov
KM 37k/ss helmet neck dam near miss
An air diver’s helmet flooded during offshore subsea work after locking pull pins caught on a recovery harness and released the collar. Free-flow over-pressurisation displaced the neck dam seal. The flash describes standby-diver assistance, missing pull-pin sleeves, workshop modifications, pre-dive checks and changes to tool placement.
- 201718 Oct
Safety Alert 325 - Bolt Failures
BSEE describes subsea connector bolt failures during a BOP high-pressure test, with leakage but no loss of well control or injury. Material suitability and heat treatment remained suspected causes under investigation. Recommendations address replacement of affected-lot bolts, material compliance, installation and maintenance procedures, and timely failure reporting.
- 201725 Jul
Near miss: Failure of subsea lifting equipment
During seabed spool removal, a load supported by two lift bags rose uncontrollably before falling back to the seabed after partial bag deflation. Investigation suggested missing hold-back lines as the immediate cause. The flash emphasises following dive plans and procedures, applying assessed mitigations and ensuring supervisor accountability.
- 201715 Jun
Near-miss: Fault spotted in subsea lifting wire
A diving team identified strand protrusion in a launch and recovery system clump weight wire during operations at 10 msw; no broken strand was confirmed. The flash recommends frequent monitoring, inspection before each dive, immediate defect reporting, appropriate load testing after changes and removal or disposal of affected rope.
- 20179 Jun
Near-misses during diving operations
Two diving near misses involved a bell approaching subsea lifting gear during vessel relocation and a stud bolt falling from a vessel towards a seabed worksite. A diver stopped the move, and dive control warned the exposed divers. Neither event caused injury or damage; subsequent arrangements included a dedicated tool basket.
- 20173 May
Lost time injury (LTI): Deadman anchor (DMA) toppled over, injuring a diver
A diver suffered a fractured fibula and torn ankle ligament when a deadman anchor overturned during holdback rigging for closing-spool installation. The substituted weight had unsuitable geometry and had not been checked for suitability. The flash examines risk assessment and change-management failures, with actions addressing rigging, procedures and supervision.
- 20173 May
LTI: Leg injury caused during HP water jetting
A diver suffered a thigh cut while cleaning a riser with a Cavitek high-pressure water jet. The flash discusses insecure positioning, incorrectly calculated hose length and a potentially unsuitable short lance. Lessons address stable mid-water working, gun balance and condition, hose arrangements, trigger handling, risk assessment and communication.
- 20173 May
Near-miss: Gas release from subsea pipeline
A gas release occurred during subsea spool connection while divers were in the bell for shift changeover. The vessel moved clear and an ROV released the crane hook safely. Findings highlight missing refinery communication about valve opening; recommendations address permit understanding, inter-site communication, H2S preparedness, drills and equipment testing.
- 20173 Mar
Near-miss: Suspected high levels of CO₂ in diver breathing gas
Two saturation divers working at approximately 92 m experienced breathing difficulties associated with elevated carbon dioxide in reclaimed breathing gas. Saturated absorbent and apparently incorrect analyser calibration were identified. The dive was aborted without further ill effects. Learning focuses on alarm settings, operating manuals, safety-critical competence and contaminated-gas emergency arrangements.
- 201713 Feb
Near miss: Unidentified differential pressure led to diver’s umbilical getting trapped
An inshore diving near miss involved an umbilical drawn into a gravity-fed seawater intake and trapped by automated cleaning equipment. A second diver cut the line, enabling both divers to surface uninjured. Findings address undisclosed automation, inadequate isolation and risk review, with corrective actions covering lockout verification and dive-tender repositioning.
- 20164 Dec
Failure to report hydraulic leak subsea
During diver monitoring of a subsea manifold valve, a hydraulic release went unrecorded and unreported. The client discovered it some four months later through video review. The flash identifies unfamiliarity with reporting procedures and unclear processes for additional works, emphasising pollution notification requirements and their inclusion in dive plans.