Commercial Diving on Construction Jobs: Scope Questions to Ask the GC

By QuickBidSetup Editorial Team · Published October 31, 2026 · Sources linked below

When bidding bridge substructures, cofferdams, marine piers, or outfalls, estimators frequently encounter underwater work scopes. Under federal safety standards, commercial diving conducted in connection with construction is strictly regulated. Specifically, 29 CFR 1910.401 applies to every place of employment within the waters of the United States and Outer Continental Shelf lands where diving and related support operations occur. Marine bidders must clarify operational scopes, diving modes, and site responsibilities with the general contractor before submitting a bid.

Is the Underwater Work Defined as Construction Diving or an Exempt Operation?

Ask the general contractor whether underwater tasks fall under commercial construction diving or if the project team assumes an exemption applies. The federal standard applies to diving and related support operations conducted in connection with all types of work and employments, including construction, demolition, ship repairing, shipbuilding, shipbreaking, and longshoring.

Exemptions are narrowly restricted to search, rescue, or public safety diving under government agency control, instructional dives using open-circuit compressed-air SCUBA within no-decompression limits, or human research governed by 45 CFR part 46. Furthermore, scientific diving is limited to scientific research tasks under a diving safety manual and a diving control board. Under 29 CFR 1910.402, scientific diving explicitly does not include:

Placing or removing heavy objects underwater
Underwater construction or demolition
Underwater cutting or welding
Inspection of pipelines and similar underwater objects
Use of explosives

Clarify this classification early and document your assumptions in your bid exclusions and clarifications.

Which Specific Diving Modes and Surface Locations Will the Site Accommodate?

Ask the prime contractor to specify the designated diving mode. Under 29 CFR 1910.402, diving modes include SCUBA diving, surface-supplied air diving, and mixed-gas diving. SCUBA functions independently of surface air lines, while surface-supplied air diving delivers compressed air from the surface dive location to the diver in the water. Mixed-gas diving uses a breathing gas other than air.

The dive location—defined as the surface or vessel from which diving is conducted—shapes mobilization costs. Ask the general contractor:

Will the dive team operate from a fixed surface, a stationary barge, or a vessel underway?
If operating from a vessel underway, is liveboating permitted on site?
Will the project require an inwater stage to support the diver in the water?
Is a bell (an open or closed compartment) required for transporting divers to the underwater work area as a temporary refuge?

Who Furnishes Primary Air Systems, Reserves, and Umbilicals?

Define equipment demarcation with the general contractor before pricing your dive team. Safety rules require independent backup systems. Ask whether the prime contractor provides air compressors or if your team must supply the complete package.

Federal rules require a dive-location reserve breathing gas supply at the surface independent of the primary supply, adequate to support divers during planned decompression. Divers must also carry diver-carried reserve breathing gas sufficient to reach the surface, reach another breathing gas source, or be reached by a standby diver stationed at the dive location. Confirm umbilical clearances for lines supplying breathing gas, communications, power, or heat with a safety line. Ensure all volume tanks and cylinders meet ASME Boiler and Pressure Vessel Code, Section VIII standards under standard working pressure.

What Bottom Times, Depth Tables, and Decompression Facilities Are Planned?

Labor pricing depends directly on bottom time, defined as the total elapsed time in minutes from when the diver leaves the surface in descent until beginning ascent. Changing depth profiles affect diving safety and should be managed through standard differing site conditions provisions.

Ask the general contractor if dives will stay within no-decompression limits under the U.S. Navy Diving Manual tables or equivalent standards. If diving exposures exceed those limits, determine whether a decompression chamber (surface decompression chamber, closed bell, or deep diving system) must be stationed at the dive location to decompress divers and treat decompression sickness. In addition, verify that the designated person-in-charge coordinates dive team activities with topside operations.

What Emergency Deviation and Agency Notification Protocols Apply?

Under 29 CFR 1910.401, an employer may deviate from diving regulations during an emergency to the extent necessary to prevent or minimize situations likely to cause death, serious physical harm, or major environmental damage. The employer must notify the Occupational Safety and Health Administration Area Director within 48 hours of the onset of the emergency and submit written details upon request. Clarify how project emergency plans coordinate this reporting.

Sources

Published October 31, 2026. No affiliate links on this page. Facts come from the sources linked above; check them for updates.