Dive Supervisor, DMT and the Documentation Your Job Legally Requires
By Ray Whitfield, ADCI-certified commercial dive supervisor. Reviewed by Amanda McCallister, editor.
Commercial Diving Contractors Alabama | Commercial Diving Contractors Alaska The current was pushing the tug hard against the cofferdam, and I could hear the diver's breathing—slow, steady—through the comms. I signed the dive log with a number two pencil because the ink was gone, and I remember thinking: this is the part they don't show you in the training videos. That signature didn't mean the dive was safe. It meant someone documented why we thought it was. People mistake the dive supervisor for the guy who yells 'dive!' on cue. In reality, he's the guy who signs off the paperwork, and that paperwork is what stands up in an OSHA inspection or a wrongful-death suit. The legal minimums for a commercial dive supervisor are not about bravery. They're about paper. I've seen inspectors walk the tie-off points and then ask for the paper. The paper is what they trust. If you're coming up through the ranks or sitting for your ADCI supervisor card, this is what you need to have ready—and why.
Your Paper Spine: The Dive Plan and Hazard Assessment
Every dive gets a plan. OSHA 1910.424 says the dive supervisor has to formulate it before each dive. It's not optional. That plan includes the task, the location, the depth and bottom time, the gas mix, the team makeup, the surface support, and the emergency procedures. I've written hundreds, and they all ended up in the same binder. That plan has to be signed before the first diver hits water. Not after. The plan is a living document. We mark revisions in ink. On a recent job at a hydro plant intake, the diver found a heavy cable across the grill that wasn't on the drawings. That changed the hazard assessment and the job schedule. We stopped the dive, wrote the change into the plan, and re-signed. The inspector later asked to see that exact page. If I'd done it verbally, we'd have been shut down. A practical digression—one time in drydock work, I had an inspector from the state actually quote 1910.424 from memory, and I matched him line for line. That's the only time I've seen an inspector smile. Know the regulation. It's the one piece of paper that can save your whole crew.
DMT: The Medical Side of the Log
OSHA and ADCI both require a DMT—Diver Medical Technician—on the dive team. On most inland jobs, that's me or my second supervisor. The DMT certification is a separate thing from the supervisor card. It has its own training, its own renewal cycle, and its own paperwork. If I'm covering a dive and my DMT card expires, the dive stops. No exceptions. The DMT training isn't a weekend course. It's a serious certification with a practical exam. The DMT maintains the medical response log. That's the oxygen supply for the first-aid kit, which happens to be a 30-minute unit, and the emergency action plan. We do a weekly drill, and we document it. There's a big difference between having oxygen on board and proving you know how to use it in a panic. When a diver comes up with symptoms—say, a shoulder ache after a long dive—the DMT records it, treats per the plan, and writes it up. That write-up is evidence if there's ever a claim. Good medical logs look like a nurse wrote them. Trust me, I've read hundreds.
Equipment Records That Hold Up in Investigation
The diving log has to show what equipment was used, how it was inspected, and who did the inspection. That means daily inspection sheets for the helmet, the harness, the umbilical, the pneumo, and the compressor. I use the brand names: Kirby Morgan masks are what I see on most jobs, and Miller harnesses, but the paperwork doesn't care about the logo. Calibration is the other side. Depth gauges, pressure gauges, gas analyzers all need a current calibration stamp or certificate. We've got a hand-held oxygen analyzer that we zero against a standard gas every morning. That's written in the log. If I can't see the date on the sticker, the inspector doesn't care what we did. It didn't happen. Every gauge on the panel gets checked against a deadweight tester once a year. That's the standard we use. On one dam job, we had a hydraulic cutter with a pressure gauge that was reading 500 psi off. The calibration certificate said it was due the prior month. It cost me half a shift to get a new one, and I caught it during the pre-dive inspection. That's what the paperwork is for—to catch the problem before the crew does.
Retention, Incident Reports, and the Twenty-Four-Hour Rule
ADCI and OSHA both want dive logs kept, but they don't agree on the exact retention—call it two years minimum, and I've kept mine for a decade. The physical way you store them matters. A black market? No, a three-ring binder with a spine label. Digital logs are fine, but they need to be backed up and tamper-proof. I also keep a separate file for each diver's exposure log, just in case. Incident reports are the one thing that has a hard timeline. If anything goes sideways—a cut umbilical, a lost pneumo, a hasty ascent—I write that incident report the same day, before the story gets smooth. The rule in my crew is twenty-four hours, but we've never made it that far. You write it while the memory is sharp and dirty, not after the lawyer says what to say. It sounds like paperwork for paperwork's sake. It isn't. I've been through three OSHA inspections on accident sites, and the first thing they do is pull the dive logs from the day before. If your logs look like a kindergartner's doodle, you're part of the problem. If they look like a pilot's flight plan, you've done your job.
Frequently Asked Questions
What does a commercial dive supervisor need to be certified? An ADCI certification—called 'Supervisor'—which requires a minimum number of logged dives, a supervisor-in-training period, and a DMT (Diver Medical Technician) certification. You have to renew both. OSHA doesn't issue its own card, but it expects you to meet the consensus standards like ADCI. Do I need a DMT on every dive? Yes. OSHA 1910.424 and ADCI both require a trained DMT at the dive station during the dive. The supervisor is often the DMT, but you have to prove it. A card with an expiration date is your proof. Can I use electronic dive logs instead of paper? Yes, but they need to be secure, uneditable after the fact, and readable by an inspector. I've used both. Paper is simpler, but digital is fine if you're disciplined. How long do I need to keep logs? OSHA says the employer must keep the dive log for at least two years, but I'd recommend longer. ADCI and insurance companies may require 5-10 years. When in doubt, keep it.