The claim that underwater welding has a "15% death rate" has no traceable primary source, and it can't be true. At 15%, several hundred US commercial divers would die every year. The Bureau of Labor Statistics recorded 39 deaths in seven years (2011–2017). The best official estimate is still the CDC's from 1998: about 180 deaths per 100,000 full-time commercial divers per year, roughly 40 times the rate for all workers. That makes diving one of the most dangerous occupations there is. The "life expectancy of 35–40" claim doesn't hold up either: it confuses the age of divers who died with how long divers live. The risk is real, it has specific causes, and regulation exists to control them.
Almost every page that ranks for this question repeats the same two numbers: a 15% fatality rate and a life expectancy of 35 to 40. Many of them are law-firm pages or blogs that sell welding gear. We tried to trace both numbers back to where they came from. We then set them against what the CDC, the Bureau of Labor Statistics, the UK Health and Safety Executive and the offshore industry have actually published.
This page is general information about occupational risk. It is not medical or legal advice about any individual case.
The short answer: what the data actually shows
Nobody publishes a death rate for "underwater welders". Like pay, it only exists within the wider group of commercial divers, and a welder is a commercial diver who welds. The usable figures are:
| Source | Finding | Period |
|---|---|---|
| CDC, MMWR 47(22), 1998 | Average of 5 deaths a year among ~3,000 full-time US commercial divers = 180 per 100,000 a year, 40× the all-worker rate | 1989–1997 (OSHA records) |
| BLS, cited by NIOSH | 39 fatal injuries and 460 non-fatal injuries with days away from work among commercial divers | 2011–2017 |
| BLS Census of Fatal Occupational Injuries | All US workers: 5,070 deaths, 3.3 per 100,000 full-time-equivalent workers | 2024 |
| Cambridge / EM&I review (2022) | Current estimates of 3–10 deaths per 10,000 divers a year (30–100 per 100,000); UK HSE data put at 2–4 per 10,000 | Various |
Sources: CDC MMWR, 12 June 1998; NIOSH, commercial diving; BLS CFOI 2024 (released 19 February 2026); A. Woods, University of Cambridge / EM&I, "A report on fatalities in commercial diving".
We can also do a rough cross-check with recent numbers. 39 deaths over seven years is about 5.6 a year. Against the roughly 4,200 US commercial divers O*NET reports for 2024 (or the CDC's 3,000), that works out at about 130–190 per 100,000. That is 40 to 55 times the 2024 rate for all workers. The calculation is ours and it's approximate: the death count and the headcount cover different years, and the headcount leaves out self-employed divers. But it matches the CDC's order of magnitude. It is nowhere near 15%.
Where the "15%" and "life expectancy 35–40" numbers come from
We followed the links on the pages that rank for this question. The trail for the 15% figure looks like this:
One personal-injury firm's blog says underwater welders "have the highest fatality rate of any occupation—15%". It links to a welding website as its source. That website says underwater welding "was listed as the top dangerous profession with nearly a 15% fatality rate" and attributes this to a 2018 study. It gives no name, no author and no link. We searched and found no primary study, government dataset or peer-reviewed paper with this figure.
A simple check shows it can't be right. A 15% annual death rate among about 4,200 US commercial divers would mean more than 600 deaths a year. The federal census of workplace deaths recorded 39 in seven years. Even if "15%" meant 15% over a whole career, it would still be several times higher than any published estimate.
The life expectancy claim seems to come from mixing up two different things. The same welding website quotes a Divers Association study of 382 recorded deaths and says "the deceased divers were between ages 33 and 42". The Cambridge review reports a mean age of 37 in a similar analysis. Those are ages at death among divers who were killed at work. They tell you nothing about how long working divers live in general. If you applied the same logic to road deaths, you would conclude that drivers die young. We found no actuarial or epidemiological study that gives a life expectancy for underwater welders or commercial divers.
What official data exists, and what it can't tell you
United States
The CDC's 1998 report is still the only official US source that publishes an actual rate for commercial divers. It focused on nine deaths in Alaska from 1990 to 1997. Three involved sea-cucumber harvesting, three involved clearing lines or nets from fishing boats, two were vessel-related work and one was Navy training. All nine were officially recorded as drowning. The national rate of 180 per 100,000 comes from the report's analysis of OSHA records: 116 occupational diving deaths over the nine-year period, 49 of them among roughly 3,000 full-time commercial divers.
The BLS Census of Fatal Occupational Injuries counts every workplace death, but it publishes rates only for occupations large enough to give stable figures. Commercial diving is too small, which is why the most recent diver-specific count (39 deaths, 2011–2017) comes via a NIOSH summary rather than as a published rate.
United Kingdom and offshore
In Great Britain, all diving at work comes under the Diving at Work Regulations 1997, and the HSE investigates incidents. The Cambridge review cites HSE figures of 2 to 4 deaths per 10,000 divers a year, and a risk "12–24 times that of the construction sector".
The offshore contractors' body IMCA publishes annual safety statistics. In 2025, 167 contractors reported 1.02 billion hours worked and seven deaths, four of them offshore. That gives a fatal accident rate of 0.69 per 100 million hours. The report doesn't separate diving from other marine work, so it can't tell you a diver's risk.
Source: IMCA Annual Safety Statistics Report 2025.
Why the rate is so hard to measure
Every rate needs two numbers: the number of deaths and the number of people exposed to the risk. For diving, both are shaky:
- Small numbers. A few deaths more or less in one year swing the rate dramatically.
- A mobile workforce. Divers move between countries, employers and payrolls. Someone killed abroad may not appear in their home country's statistics.
- Who counts as a diver. Some datasets include fishing divers, aquaculture divers and scientific divers. Others don't. The CDC's Alaska deaths were mostly in harvesting and fishing work, not construction.
- Time in the water. A diver who works 80 days a year is exposed very differently from one who works 200. Few sources measure risk per dive or per hour.
How divers actually die
Official reports and industry reviews point to a consistent set of causes. Welding is only one of them, and not the biggest.
| Cause | What happens | Evidence |
|---|---|---|
| Drowning after equipment or gas-supply failure | The breathing gas supply fails, runs out or is cut off, and the diver can't reach the surface | CDC 1998: drowning was the recorded cause in all nine Alaska deaths; equipment failure and exhausted air supply among contributing factors |
| Entrapment and differential pressure (delta-P) | The diver is pinned against an opening where water is flowing through (intakes, pipes, dam gates) | Cambridge review: about a quarter of deaths in one analysis; "other than being trapped, the risks for each cause are similar" |
| Entanglement | Lines, nets or wires hold the diver down | CDC 1998 (2 of 9 Alaska cases); Cambridge review |
| Decompression illness | Gas bubbles form in the body during or after ascent | Cambridge review; see decompression sickness |
| Propellers and vessel movement | Contact with thrusters or moving hulls | Cambridge review |
| Electric shock and explosion | Welding or cutting current, or ignition of trapped gas | Cambridge review lists "underwater welding, causing burns or explosions" |
The Cambridge review sums up the historic pattern as "poor supervision; poor planning and safety management; equipment failure and dangerous environments." Most of those are organisational failures, which regulation and good contractors can fix. How investigators reconstruct these chains of events is covered in how diving accidents are investigated.
Risks specific to wet welding: electric shock and gas explosions
Welding adds two hazards to the ordinary risks of diving. Both are described in detail in the US Navy Underwater Cutting & Welding Manual (S0300-BB-MAN-010).
Electric shock. Wet welding runs an electric arc in seawater, which conducts electricity. The Navy manual forbids AC power for underwater cutting and welding "due to the extreme danger involved with AC current underwater". AC shock can make the muscles clamp so the diver can't let go. The manual also warns never to get between the electrode holder and the ground (the earthing point on the work) while the current is on. It describes the splash zone, where the diver is only partly in the water, as the most dangerous place to be. The practical controls, including isolation and lock-out, are covered in electrical risk and LOTO underwater.
Gas pockets and explosions. The arc splits water into hydrogen and oxygen. The manual warns that these gases "will explode if trapped and ignited". They collect in closed compartments, open pipes, tubular members and under beams. The manual says that before cutting begins, it is mandatory to vent existing gases and prevent new ones from building up. OSHA's rules say the same thing for welding on closed compartments or pipes that may contain flammable vapour.
The differences between wet and hyperbaric (dry habitat) welding, including how they affect these risks, are explained in wet vs hyperbaric welding.
Long-term health
Deaths are the headline figure, but most of the lasting harm in the trade builds up slowly. Divers face a known set of long-term occupational health problems. They include bone damage linked to decompression (dysbaric osteonecrosis), hearing problems, and wear on joints and the spine from heavy manual work in cold water. That is why commercial divers need a medical assessment before they're allowed to dive, and regular ones after that. We cover these problems and how they limit a working life in chronic injuries and the diver's working life. For deep work specifically, see is saturation diving dangerous?
What reduces the risk
The CDC report makes the key point itself: only one diver with commercial dive training had died in Alaska since the 1960s, and its recommendations focus on training, standby divers, reserve air and equipment maintenance. It also notes that recreational diving certification is not enough training for commercial diving work. Regulation is built around the same ideas.
| Control | US (OSHA 29 CFR 1910 Subpart T) | UK (Diving at Work Regs 1997) |
|---|---|---|
| Training and competence | Every dive team member must have training or experience for their tasks, plus CPR and first aid (1910.410) | Divers must hold an approved qualification (reg. 14) and a certificate of medical fitness (reg. 15) |
| Someone in charge | A designated person-in-charge at the dive location (1910.410(c)) | A named diving contractor (reg. 5–6) and an appointed supervisor (reg. 9–11) |
| Planning | Pre-dive assessment of hazards, gas supply, emergency procedures (1910.421) | A written diving project plan (reg. 8) |
| Backup in the water | Standby diver and reserve gas for dives deeper than 100 fsw or outside no-decompression limits (1910.425) | Set out in HSE's Approved Codes of Practice for each type of diving project |
| Welding controls | Current switch tended by a team member in voice contact and kept open except while welding; grounded machine frame; insulated gloves; closed spaces vented or flooded (1910.422(g)) | Covered by the diving project plan and risk assessment |
Sources: OSHA 29 CFR 1910 Subpart T (in particular 1910.422 and 1910.425); Diving at Work Regulations 1997.
In practice, the checklist is short. Before you accept any diving job, and especially one with welding, check:
- Is there a named supervisor on site who is not diving?
- Is there a standby diver dressed in and ready?
- Does the diver have a reserve gas supply (bailout)?
- Is the welding current switched by a team member who can hear the diver?
- Have intakes, pumps and gates that could create differential pressure been isolated and locked out?
- Have closed spaces been vented or flooded before any hot work?
If any answer is "no" or "we don't do that here", you have learned something important about that contractor.
Whether the risk is worth it also depends on the pay, which varies a lot more than most pages admit. Our underwater welder salary breakdown has the official figures. If you decide to go ahead, the route through school and weld qualification is set out in how to become an underwater welder.
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Frequently asked questions
What is the life expectancy of an underwater welder?
No study we could find publishes a life expectancy for underwater welders or commercial divers. The "35 to 40 years" figure appears to mix up the age at death of divers killed at work with how long divers live. One analysis quoted online gives ages at death of 33 to 42, and a Cambridge review reports a mean of 37. Those figures describe people who died on the job, not the whole workforce.
Is underwater welding the most dangerous job?
It is among the most dangerous, but no official ranking lists it, because the BLS does not publish a rate for such a small group. The CDC estimated 180 deaths per 100,000 full-time US commercial divers a year, about 40 times the all-worker rate at the time. In 2024 the rate for all US workers was 3.3 per 100,000. Underwater welders are commercial divers, so the same range applies.
How many underwater welders die each year?
Nobody counts welders separately. The BLS recorded 39 fatal injuries among all US commercial divers from 2011 to 2017, about 5 to 6 a year. The CDC's earlier analysis found an average of 5 deaths a year among full-time US commercial divers from 1989 to 1997. Worldwide figures are incomplete; one analysis cited by a Cambridge review counted 392 commercial diving deaths from 2002 to 2014.
Is the 15% underwater welding death rate true?
No. We found no primary source for it: the pages that repeat it cite each other or an unnamed "2018 study". It also fails a simple check. A 15% annual rate among about 4,200 US commercial divers would mean more than 600 deaths a year, while the BLS recorded 39 in seven years. The real rate is still very high, roughly 40 times the average for all jobs.
Sources
- CDC, "Deaths Associated with Occupational Diving — Alaska, 1990–1997", MMWR 47(22), 12 June 1998.
- NIOSH, Maritime Safety and Health: commercial diving (BLS data 2011–2017; page updated 3 January 2024).
- US Bureau of Labor Statistics, National Census of Fatal Occupational Injuries in 2024, released 19 February 2026.
- A. Woods, Institute of Energy and Environmental Flows, University of Cambridge / EM&I, "A report on fatalities in commercial diving" (2022).
- IMCA, Annual Safety Statistics Report 2025; IMCA safety statistics archive.
- OSHA, 29 CFR 1910 Subpart T — Commercial Diving Operations; OSHA commercial diving overview.
- UK, Diving at Work Regulations 1997 (SI 1997/2776); HSE diving.
- US Navy, Underwater Cutting & Welding Manual, S0300-BB-MAN-010 (Internet Archive copy).
- O*NET OnLine, 49-9092.00 Commercial Divers (2024 employment).
- Claims traced: law-firm blog and welding blog, checked September 2026.
Published 28 September 2026. Figures checked on 28 September 2026 against the sources above. Found an error or a newer figure? Tell us.
Photo: oskay · CC BY via Openverse