Nine divers died in UK diving incidents during 2025, according to the latest annual safety report from the British Sub-Aqua Club (BSAC), which also highlights decompression illness, drysuit buoyancy problems and the importance of effective rescue procedures.
The newly released report records 220 diving incidents in the UK during 2025, alongside another 85 incidents overseas, bringing the total to 305.
Published by BSAC in October 2026 and formally announced on 2 November, the findings provide one of the most comprehensive annual examinations of recreational diving safety in British waters.
Compiled by diving safety and incidents advisor Jim Watson and data analyst Ben Peddie, the BSAC Annual Diving Incident Report 2025 draws on reports from individual divers, training organisations, emergency services and other relevant bodies.
While the nine fatalities represent a reduction from the 12 recorded in 2024, the report identifies several areas where divers, instructors and dive operators can learn important lessons.
Nine Diving Deaths, With Causes Not Always Established
The nine people who died in UK diving incidents during 2025 had an average age of 55.
Three fatalities involved dives deeper than 50 metres, all conducted using rebreathers. Immersion pulmonary oedema (IPO), a potentially life-threatening condition involving fluid accumulating in the lungs, was confirmed as the cause of one fatality.
Medical or physiological factors were implicated in at least one additional death.
One diver died during preparations for a dive, before entering the water.
However, BSAC cautions that insufficient information was available to establish firm conclusions about the causes of death in more than half of the fatal cases.
This distinction is important. The involvement of particular equipment, diving depths or medical conditions does not necessarily establish what caused an individual fatality.
The report’s findings reinforce the need for continued attention to diver health, preparation, appropriate training and emergency procedures, while recognising that serious incidents can involve several contributing factors.
Decompression Illness Incidents Increase to 53
Another significant finding concerns decompression illness (DCI).
BSAC recorded 53 UK incidents involving DCI during 2025, compared with 37 during 2024, an increase of approximately 43%.
Despite this year-on-year increase, the report’s longer-term analysis suggests that the previous decline in reported DCI incidence has begun to level out rather than showing a sustained upward trend.
The findings also indicate a change in the relative importance of contributing factors.
Cases associated with dives deeper than 30 metres and missed decompression stops have become less prominent in the historical data, while repetitive diving accounts for a growing proportion of reported DCI incidents.
This does not mean that repetitive diving is inherently unsafe or that deeper diving and missed stops are no longer important risks. Rather, the findings demonstrate why cumulative exposure, dive planning and appropriate conservatism remain relevant even when individual dives appear uneventful.
BSAC also emphasises that decompression illness can develop without an obvious error or unusual event during a dive.
Divers should therefore take potential symptoms seriously, even when their dive computer indicates that planned limits were respected.
Drysuit Inversion Emerges as a Significant Safety Concern
One of the report’s most substantial areas of analysis examines drysuit inversion incidents over a 25-year period.
These incidents occur when gas migrates into the legs or boots of a drysuit, potentially causing the diver to become inverted and lose control of buoyancy.
The situation can become particularly dangerous when the diver is unable to return upright or release expanding gas, resulting in an uncontrolled feet-first ascent.
BSAC found that drysuit inversion accounted for 7.1% of reported early-season UK diving incidents between January and April during 2021–2025, approximately double the historical rate.
The analysis identified several recurring contributing factors, including poorly fitting drysuits, oversized boots, unfamiliar undersuits and changes in equipment configuration.
Divers using borrowed, newly purchased or recently modified drysuits appeared in a number of the incident reports.
Problems with weighting, inflation valves and dump valves were also identified.
However, the investigation found that equipment malfunction alone was rarely sufficient to explain an inversion incident.
Instead, a combination of buoyancy management difficulties, equipment unfamiliarity, diver positioning, additional tasks and stress could cause situations to escalate rapidly.
Although the report identifies a recent increase in early-season inversion incidents, BSAC notes that the smaller dataset does not establish a statistically significant change in the underlying causes.
Why Drysuit Familiarity Matters
The findings carry particular relevance for divers returning to the water after an extended break, changing equipment or beginning their first season of drysuit diving.
Correctly fitting boots are especially important because excessive movement inside them can make it difficult for an inverted diver to regain control.
BSAC’s recommendations include reviewing weighting, checking inflation and dump controls, becoming familiar with equipment before demanding dives and regularly practising inversion recovery techniques.
The report also highlights the importance of managing task loading, particularly when handling reels, deploying delayed surface marker buoys or conducting other activities that can affect body position and buoyancy.
The wider lesson is that even experienced divers can encounter difficulty when equipment behaves differently from what they expect.
Immersion Pulmonary Oedema Remains a Concern
The report also identifies six confirmed or probable cases of immersion pulmonary oedema during 2025, comprising three medically confirmed and three probable incidents.
IPO can cause breathing difficulties during immersion and may develop without the diver initially recognising the seriousness of the problem.
BSAC suggests that improved awareness among divers, instructors and medical professionals is helping the condition to be identified earlier, potentially preventing incidents from becoming more severe.
Warning signs may include unexpected breathing difficulty, persistent coughing, confusion or an unusual sensation that a regulator is not supplying sufficient gas.
BSAC’s guidance advises divers experiencing breathing difficulties underwater to terminate the dive, ascend safely and exit the water. Emergency oxygen and prompt medical assessment are important parts of the subsequent response.
Further information is available through BSAC’s guidance on immersion pulmonary oedema.
Emergency Services Respond to Dozens of Diving Incidents
The report also illustrates the significant role played by emergency services in supporting recreational diving.
During 2025, HM Coastguard coordinated responses to 98 diving incidents, while the Royal National Lifeboat Institution (RNLI) recorded 21 lifeboat call-outs.
Search and rescue helicopters were deployed on 22 occasions.
These figures demonstrate the importance of maintaining effective emergency procedures, both aboard dive boats and at shore-diving locations.
BSAC notes that prompt intervention by fellow divers and emergency responders frequently prevents serious incidents from developing into more severe emergencies.
The findings also reinforce the importance of rescue training, familiarisation with emergency equipment and early notification when assistance may be needed.
What the Report Means for UK Divers
Although diving activity has returned to levels comparable with those before the pandemic, the number of reported UK incidents has remained relatively stable over much of the past decade.
Incident numbers alone cannot establish whether diving is becoming more or less dangerous without reliable information about participation, dive frequency and exposure.
Nevertheless, the annual report provides valuable insight into the circumstances that can contribute to diving emergencies.
Its findings suggest several practical areas deserving attention: medical fitness, appropriate dive planning, familiarity with equipment, buoyancy skills, recognition of decompression illness symptoms and the ability to respond effectively when another diver needs assistance.
Importantly, the report also demonstrates that experience and advanced qualifications do not eliminate the possibility of an incident.
Learning From Incidents Rather Than Repeating Them
The BSAC incident reporting programme is intended to support the entire diving community, regardless of training agency or experience level.
Information submitted by divers helps identify recurring problems and supports improvements in training, equipment guidance and emergency response procedures.
Divers who have experienced or witnessed an incident, including a near miss, are encouraged to submit a confidential report through BSAC’s diving incident reporting system.
The full Annual Diving Incident Report 2025 is available to read online.
For the diving community, the most important value of the report is not simply the number of incidents recorded, but the opportunity to understand what happened, identify preventable risks and apply those lessons before the next dive.
