Why Two Dive Bids for the Same Job Differ by 300%

By Priya Raghunathan, Port authority procurement analyst. Reviewed by Amanda McCallister, editor.

Underwater Inspection | Marine Construction Last month I opened two bids for a sacrificial anode replacement at the north pier. One came in at $18,200, the other at $58,750. Same scope, same drawing, same tide tables. I called the higher bidder's estimator and asked, 'What am I missing?' He laughed. 'Everything,' he said. I've done this long enough to know a three-to-one range on dive work is normal. That doesn't mean it's irrational. The market is thin, the work is dangerous, and the difference between a cheap bid and an honest bid is often the difference between a fatality and a near-miss. If you're chasing underwater contracts, here's how to read the spread.

You're hiring a team, not a diver

On a standard commercial dive, you're paying for four people: the diver, the dive supervisor, the standby diver, and the tender. Sometimes there's also an entry-level trainee or a first-aid attendant. At a typical rate of $750–$1,200 an hour for a complete dive team, give or take, a ten-hour day runs $7,500–$12,000. That's before a single bolt has been turned. Add the topside equipment: a Kirby Morgan KMB 28B helmet ($6,000), a hot water suit for cold water ($3,000), a Mako compressor ($30,000), plus comm boxes, bailout bottles, and the maintenance ledger. A full spread can be worth $40,000 or more. The bidder has to cover that across the days they actually work. Some owners get the same gear for two days, others for three months. Location shifts the rate, too. A warm-water dive off the Gulf coast might run $750 an hour. Push into the Bering Sea and that same team bill doubles—and suddenly you need an enclosed hot-water suit and a closed bell. So don't compare a Maine harbor job with a Puget Sound job. Some bidders already own the gear. Some rent it per job and pass through the daily cost. Some bring the absolute minimum and hope the water stays warm and clear. Which one do you want on your north pier?

Mobilization isn't just truck mileage

Mobilization isn't just truck mileage. It's a boat, a crane, and often a barge. A 20-by-8 barge from a local contractor runs $1,200–$2,500 a day depending on the season. A crane barge? That's $3,500–$5,000 a day. If the port supplies a workboat, the bidder will strip it out of their price. If not, it's a line item. Depth and current change every price. A dive in ten feet of flat water is a different animal from a dive in sixty feet with three knots of current. Deeper water means more decompression obligations, more reserve gas, and stricter supervision. That can double the labor rate. One digression: a few years back, a contractor bid $12,000 for a pier survey that we thought would cost $30,000. He didn't account for the local current. On day one, his diver couldn't hold bottom for more than fifteen minutes. He ended up mobilizing an ROV. The ROV alone cost $12,000 a day. He finished at $48,000 and filed a claim. We paid it because the contract said 'to completion.' I've never made that mistake again. That same job taught me to force bidders to address current explicitly. Now I ask them to state the assumed max current and visibility. If the numbers don't line up, we talk. That one question has eliminated more than a few fantasy bids.

The client's unknowns are priced in

No owner has perfect information about what's underwater. Even with drawings, you don't know if the anode faces are solid or skeletal, or whether the environmental permit changed the schedule. So every bid is partly a bet. A contractor with in-house engineers will price in a reasonable worst case. A hungry two-man outfit will hope for a benign bottom. The difference can be enormous. That's why a pre-dive ROV survey or a video diver is so valuable. It shrinks the spread. I've seen ROV surveys turn a $30,000 gap into a $6,000 one. For instance, on one project we found a sleeping sea lion on the pier leg. That wasn't in the scope. It cost us four hours and a boat to wait for it to move. The diver's time still ran. The low bidder didn't budget for any of that. If your RFP doesn't include a site walk or a chance to talk to the diving supervisor, you'll get bids that are all over the map. And that's your fault as the buyer, not theirs.

Insurance, bonds, and penalty clauses

A dive company's insurance package varies. Marine liability, workers' comp, and surety bonds are not one price. A firm with a clean safety record pays less; a startup pays more. That inescapable overhead shows up as a percentage line. I've seen 8% on one bid and 15% on another for the same job. A liquidated damages clause shifts risk to the contractor. They'll price it. The ones that don't either have a legal team they trust or a plan to fight later. Neither is good for you. Also watch how the bidder prices schedule. Portal-to-portal pays from when they leave the truck to when they're back. Diver-in-water pays only for actual dive time. On a long job, weather interruptions can double the cost under an hourly model. A lump sum protects you from that, but you'll pay for the risk up front.

How I run a bid tabulation now

I require a cost breakdown: dive team labor per day, equipment per day, mobilization lump sum, consumables per day, contingency line item, overhead. I ignore the total until I've read the assumptions. One bidder might assume two dives per day, another one. That's a twenty-hour difference. I also ask for the dive supervisor's resume and the list of certificates. Twenty years in a working harbour is different from a year of hobby diving. It shows in the questions they ask. At the end, I always ask: 'If you were me, what's one thing you'd add to this scope to make the job safer?' The good bidders give me a list. The bad ones say it's already perfect. That moment tells me more than any price. The bottom line? A 300% spread is not a mistake. It's a series of real choices. Your job as the buyer is to make those choices visible and predictable.

Frequently Asked Questions

Why do two dive bids for the same job differ by 300%? Because dive work is priced on assumptions about water conditions, equipment, and schedule risk. One bidder may include a ROV-equipped barge and a decompression chamber, while another only sends a lone diver and a rubber boat. The range reflects real differences in what you'd actually get on site. What's a typical daily rate for a commercial dive team? For a two-man dive team with a supervisor and a standby diver, expect $3,000–$6,000 per day depending on location and water temperature. Add mobilization, equipment rental, and contingency, and it's easy to hit $10,000–$15,000 per day by the time you include a barge and a crane. How can I get better, more comparable dive bids? Provide a detailed scope with a mandatory site walk, a known baseline for water visibility and current, and ask for a breakdown of labor, equipment, mobilization, and contingency. Also, supply your own pre-dive ROV video or inspection report. That removes a lot of guesswork. Is the cheapest dive bid always the worst? No, but it's usually the riskiest. A low bidder might have lower insurance, older equipment, or skimpy supervision. Ask for a safety record and the dive supervisor's background. The cost of a failed dive job in penalties and rescheduling is often more than the difference between a $25,000 and a $60,000 bid.