What is a sea trial? It's the run on the water before a boat sale closes. In most used boat deals it happens on survey day, as the underway part of a pre-purchase marine survey. The surveyor uses the run to watch the engines and systems work under load, and the buyer gets a feel for how the boat rides. And somebody has to drive.
People use "sea trial" and "survey" like they mean the same thing, and the roles get blurry too. Below I sort out who does what, what a survey costs according to published rates, and how to set up the day around Ocean City or the Chesapeake Bay.
What is a sea trial on a used boat purchase?
A sea trial is a short run away from the dock so the buyer and the surveyor can see the boat operate. On a pre-purchase survey it sits alongside the in-water inspection and the haul-out. The seller drives, or a captain is hired to.
BoatUS draws a fine line in its February 2026 guide, The Boat Survey. What happens on survey day is technically a "trial run," a short trip so the surveyor can look at the engine and running gear, while a true sea trial tests the boat in heavy seas. In everyday use, "sea trial" means the survey day run.
The buyer can ask for a few minutes at the helm to feel the boat. Beyond that, BoatUS says neither the buyer nor the buyer's broker should run the boat because of liability, especially leaving or returning to the dock.
Sea trial vs survey: who does what
The buyer decides. The accredited marine surveyor evaluates condition and value. The captain runs the boat the way the surveyor asks, and the seller or broker sets up the day. Keeping those jobs separate protects everyone in the deal.
- The buyer hires and pays the surveyor and owns the report. As BoatUS puts it, the surveyor works for you, not the seller or the broker.
- The marine surveyor inspects the boat in and out of the water, watches it run and reports findings and a value. Long Bay Marine, a SAMS accredited surveyor in Myrtle Beach, says a surveyor should never tell you whether to buy.
- The captain drives: idle, cruise, full throttle, turns, whatever the surveyor wants to see. Then the boat goes back tied up the way it was found.
- The seller and broker make the boat available, coordinate the boatyard and keep the day on schedule.
Captain, not surveyor. I hold a 100 Ton USCG Near Coastal Master license. I'm not an accredited marine surveyor, so I don't judge the boat for the sale. For that, hire an accredited surveyor through SAMS (the Society of Accredited Marine Surveyors) or NAMS (the National Association of Marine Surveyors).
NAMS notes on its About Marine Surveying page that marine surveyors aren't required to be licensed by any national or state body, which is why accreditation matters. BoatUS adds that some insurers only accept one association or the other, so ask before you book.
Sea trial vs marine survey at a glance
| Sea trial | Pre-purchase marine survey | |
|---|---|---|
| Who does it | Seller or a licensed captain drives; surveyor and buyer ride along | Accredited marine surveyor (SAMS or NAMS) |
| What it covers | The boat running underway: cold start, cruise, wide open throttle, handling | In-water inspection, haul-out below the waterline, the trial run, written report and value |
| Who pays | Captain fee and fuel: agree it up front (often the buyer or whoever books the captain) | Buyer pays the surveyor and the haul-out |
| How long | Usually fits in a half day, including the run to the yard | Most of a day on site; written report a few days later |
The different kinds of marine surveys
A sea trial is one piece of a pre-purchase survey. The other surveys are separate jobs written for different readers.
- Pre-purchase survey (condition and value). The most detailed one. BoatUS says most standard pre-purchase surveys need three things at minimum: an in-the-water survey, a haul-out, and a trial run. The haul-out is usually a quick "short haul" on the yard's lift so the surveyor can see props, anodes, struts and the hull below the waterline.
- Insurance survey. Long Bay Marine describes this as the survey an insurer requests to decide whether a boat is an acceptable risk, focused on structure, safety items and market value. Insurers often want one on older boats or for a new policy.
- Appraisal or value survey. Ordered by a lender or an attorney to set fair market value for financing or a legal matter like an estate.
- Engine survey. BoatUS recommends a mechanic trained on that specific engine, especially when the engines are a big share of the boat's value, because most general surveyors aren't set up for in-depth engine diagnostics.
What the surveyor watches during a boat sea trial
This is the surveyor's work, not the captain's. According to the BoatUS survey guide, the surveyor wants to see the exhaust the moment the engine starts, to catch excess smoke, so ideally the engines sit for 24 hours beforehand for a true cold start. The engine gets run to full capacity to see that it doesn't overheat or show strain. A good share of the run, the surveyor is in the engine compartment taking temperature and RPM readings and looking for leaks that don't show up at the dock.
The person at the helm just needs to follow directions: maybe a few minutes at idle, a long run at cruise, wide open, then a hard turn, all while keeping the boat safe with the surveyor's head in the engine room.
Pro tip: Have the surveyor send their underway list a day or two ahead so the captain can plan the route and time on the water around it.
How much does a marine survey cost?
Most surveyors charge by the foot of boat length. Published pre-purchase rates from two East Coast surveyors run $28 to $45 per foot, with minimum fees on smaller boats.
Here's what surveyors and BoatUS have actually published:
- Boston Marine Surveyors lists 2025/2026 rates of $28 to $30 per foot for a pre-purchase survey (including sea trial if applicable) and $22 to $24 per foot for an insurance survey.
- Long Bay Marine in Myrtle Beach lists $30 to $45 per foot for a pre-purchase survey with a $1,200 minimum, and $30 to $35 per foot for insurance and value surveys with a $1,100 minimum.
- BoatUS puts an engine survey at about $500 per engine in its 2026 guide, and says that with every type of survey plus a haul-out you could be looking at a $3,000 day.
- A 2014 BoatUS article, Seven Ways to Avoid the Boat Buyer Blues, gave $15 to $30 per foot.
To put the per-foot numbers in context: a 32 foot boat at Boston's published rate works out to $896 to $960 for the pre-purchase survey. At Long Bay's rate it's $1,200 (the minimum) to $1,440. Add the yard's haul-out charge and an engine survey on twins, and the total climbs. Rates vary by region, so call surveyors near where the boat sits.
Logistics: who books what and who pays
BoatUS recommends starting the survey process as soon as an offer is accepted and leaning on the broker to coordinate the buyer, seller, surveyor and boatyard.
The surveyor and the haul-out
The buyer chooses and pays the surveyor. Haul-out fees are the buyer's responsibility too, per BoatUS. Long Bay Marine spells out its own policy: the haul-out (with bottom cleaning) and a qualified person to run the boat during the sea trial have to be arranged before survey day, and those costs belong to whoever requested the survey.
The captain and fuel
A sea trial captain is usually paid by whoever books them, often the buyer or the broker. There's no single rule, so agree it up front in writing, along with who pays for fuel.
Insurance approval of the operator
During the sea trial the boat still belongs to the seller, so the seller should check with their insurer about who can run it. Many yacht policies name approved operators or want to sign off on a paid captain first, so make that call a few days ahead.
Timing, weather and the report
Long Bay Marine says a survey generally takes 4 to 8 hours. My part, the runs to the yard and the underway portion, usually fits in a half day. If the day runs past 4 hours, it bills at the $750 day rate. Watch the forecast and the tide. Wind against an outgoing tide at an inlet, or a steep Chesapeake chop, can make a run pointless or unsafe, so pencil in a backup date. BoatUS notes the report typically takes three to four days and suggests setting the purchase agreement's acceptance date at least a week after the survey.
Why brokers hand the sea trial to a licensed captain
Plenty of sellers drive their own sea trial, and BoatUS treats that as normal. The catch is that it puts the person with the most riding on the deal at the helm while the buyer watches. A broker can hand that job to a licensed sea trial captain, so the seller isn't the one deciding how hard to push the boat.
That's the work I do. I hold a 100 Ton USCG Near Coastal Master license and have been a licensed captain since 2018. I ran 48 to 78 foot crewboats for two years and ran Sea Quenched Private Charters in Ocean City for three seasons. In October 2026 I was one of two captains, with a mate, on a Hunt Ocean 56 from Annapolis to Fort Lauderdale for the boat show. I'm also a CAPCA member. On a sea trial I run the boat the way the surveyor asks. I stay out of the negotiation, and I keep my opinion of the boat to myself.
Rates are posted. A half day (up to 4 hours) is $450 and covers most sea trials. Dealers and brokers booking multi-day work get $650 per day. For how that compares with other published rates, see my guide to boat captain cost. Owners who want a captain for a delivery or a day on their own boat can look at captain services, and the background on license types is in what a USCG licensed captain is.
Need a captain for a sea trial?
I run sea trials for brokers and buyers across Delmarva, the Chesapeake Bay and Delaware Bay. Send me the boat and the survey date. Most sea trials fit in a $450 half day.
Sea trial and marine survey FAQ
What is a sea trial?
A sea trial is a run on the water before a boat sale closes. In most used boat purchases it's the underway part of the pre-purchase survey, with the seller or a hired captain driving.
Is a sea trial part of a marine survey?
Usually. BoatUS says most standard pre-purchase surveys include an in-water survey, a haul-out and a trial run. Insurance and engine surveys are separate jobs.
How much does a marine survey cost?
Published pre-purchase rates run $28 to $30 per foot (Boston Marine Surveyors) and $30 to $45 per foot with a $1,200 minimum (Long Bay Marine). Haul-out and engine surveys are extra; BoatUS puts an engine survey at about $500 per engine.
Who pays for the sea trial and haul-out?
The buyer normally pays the surveyor and the haul-out. The captain is usually paid by whoever books them. Agree on captain fees and fuel in writing before survey day.
Can the sea trial captain tell me whether to buy the boat?
No. The captain runs the boat and stays out of the deal. Judging condition and value is the job of an accredited SAMS or NAMS surveyor, and the decision belongs to the buyer.