8 Things That Void a Marine Contractor's Insurance

By Priya Raghunathan, Port authority procurement analyst. Reviewed by Dana Whitcombe, technical reviewer.

Marine Construction | Boat Lift Installation October 16, 2022. Port of Oakland, 8 a.m. The pre-bid conference had just wrapped, and a contractor from Texas pulled me aside. He had the lowest price by $214,000. He asked: 'Why do you care about the insurance declarations? It's just a piece of paper.' I cared because five months later, after a decompression incident on a similar job, I watched an insurer walk away from a $500,000 claim. The contractor had failed to have a certified dive supervisor on board that day. The policy was 38 pages. He never read the conditions. I've spent eight years scoring underwater services RFPs for the port authority. I read every certificate, every exclusion, every endorsement. I've seen contractors disqualified for missing a signature, and claims voided because a diver stepped outside a planned entry point. Marine insurance isn't a rubber stamp. It's a contract with limits, conditions, and house rules. Violate one of those rules, and the policy doesn't just fail to pay out—you become a liability to your client, your crew, and your bond. Here are eight things that will void your coverage, all of them real, all of them avoidable.

1–2. Certification and Scope Creep

1. Diving deeper or longer than your certified limits. Every commercial diver has a no-decompression limit. The plan said 100 feet max. The contractor went to 130 on air because the job was almost done. The insurer flagged the discrepancy in their own documentation and voided the claim. The reason: you represented that you would stay inside a risk envelope, and you didn't. If you need to go deeper, get a mixed gas endorsement in writing before you splash.
2. Working outside your policy's navigational limits. A vessel with an inland salvage policy that gets towed out to deep water isn't covered there. The policy's 'navigational limits' are there because the underwriter priced the exact waters you'll work. I once saw a contractor lose a claim because he was working inside the breakwater instead of in 'port and harbor operations.' The policy didn't cover the harbor side. The reason: a different body of water means a different risk profile. Every shift in location is a trigger to re-read the coverage.

3–4. The Dive Team and Supervision

3. No certified dive supervisor on site. Most marine policies require a supervisor with valid ADCI or IMCA certification. If that person is off 'sick' and you send divers down anyway, you're out of contract. The reason is simple: supervision is the quality control that prevents decompression incidents and entanglement. Without it, the insurer presumes negligent behavior. I watched a port claim denied because the supervisor was on a lunch break during a four-diver operation.
4. Using uncertified subcontractors or day labor in the water. You cannot add a body to the dive crew without adding them to the policy or confirming they have separate coverage. A contractor once borrowed a rigger from a crane barge to 'tend the lines.' The rigger had never been trained on the standby air panel. When a line tangled and a diver was pinned, the rigger panicked. The subsequent claim was denied because the rigger wasn't a certified dive tender and wasn't listed on the policy. That voided the entire contract's coverage.

5–6. Equipment and Environmental Exceptions

5. Diving in contaminated water without HAZWOPER certification and proper protective suits. When the harbor water holds a bacterial spike or chemical sheen, a standard wetsuit isn't protection. Policies list 'pollution conditions' as a separate category. If you enter a designated hazardous zone without declaring it, you've voided the policy. The reason: you knowingly increased health risk. I've seen a port inspector shut down a job when a diver surfaced with a sheen on his face mask. The insurer took hours to void the policy.
6. Using non-compliant, expired, or modified equipment. Insurers require that all equipment—compressors, hoses, hard hats—meets manufacturer specs and inspection intervals. A dive shop compressor without an ASME rating? Void. A lifting bag patched on the pier with duct tape? Void. An air hose overdue for hydrotesting? Void. The insurer will argue the equipment failure caused the injury, and without maintenance records, you're presumed negligent.

7–8. Procedures, Reporting, and Subcontracting

7. Deviating from the approved dive plan or the port's job-safety analysis. Every port RFP includes a JSA. The dive plan is part of your bid. Change the bottom time or safe entry point after award, and you're out of compliance. Insurers treat the written plan as the basis of coverage. Surfacing 200 feet from the planned exit to avoid a current? Void. The reason: they underwrote that exact plan, not your improvisation.
8. Failing to report a near-miss or incident within the policy's reporting window. Most marine general liability policies require immediate notification—often within 48 hours—of anything that could give rise to a claim. A blown line and a close call feels like routine harbor life. Not reporting it makes it grounds to deny the later claim. The reason: the insurer needed the chance to investigate, mitigate, and manage. When you go quiet, you're breaking a condition of coverage.

Frequently Asked Questions

Can I buy a policy that covers all these edge cases? Yes, but only if you're honest in the application. A marine contractor can add endorsements for deeper diving, pollution, contaminated water, and extra subcontractors. Every change in scope costs more. It's much cheaper than facing a voided claim. Read the policy forms and ask your broker about each of these conditions before you sign. What should I check on a contractor's insurance before I hire them? For a port authority, I check three things: the policy's declaratory pages for navigational limits, the exclusion list for pollution, and the safety supervisor certification attached to the bid. I also look for an evidence clause that says the insurer has no right to retroactively void coverage. If you're the client, require that the contractor names you as an additional insured—and ask for a copy of the actual policy, not just a certificate. What does 'void' mean for the project liability? If the contractor's insurance is voided, the contractor becomes personally liable. A port authority can pass the liability down to the contractor through a hold harmless agreement. But if the contractor is underinsured, the port might end up paying out of its own pocket. That's why we check the details so closely.