A USCG captain’s license requires 360 days of documented sea service since age 16, with 90 of those days (three months) within the seven years before you apply. One day means at least four hours underway on a vessel under 100 gross tons. You document it on Coast Guard Form CG-719S.
Sea time confuses a lot of aspiring captains. Not because the time is hard to get, but because the rules around what counts, how it’s measured, and how you prove it trip people up. Get one detail wrong and your application stalls at the National Maritime Center.
We’ll lay out exactly what the Coast Guard counts, how many days you need for each license, and how to document it cleanly the first time.
Sea service is the lifetime experience you build operating or working aboard boats, whether recreational, commercial, or military. Sea service for a captain’s license counts only when the vessel is underway and you’re filling a deck or engineering role, not riding as a passenger. It starts accruing the day you turn 16 and adds up across your lifetime.
Line handling, standing lookout, steering, and other navigation duties all count. Sitting as a passenger doesn’t, which is why time aboard a cruise ship as a guest earns you no credit. Your experience also has to be on a vessel with at least a 5-horsepower engine and no more than 200 gross tons (GRT).
Keep your own copies of every record, since you’re responsible for backing up what you claim. For the bigger picture, see our overview of sea time documentation.
Here’s where the corrected numbers matter. The sea service requirement for a captain’s license is 360 days total, and 90 of those days (three months) must fall within the seven years right before you apply. That three-year window is the recency rule, and it’s the piece people most often get wrong.
The total days depend on the license and route you want:
One clarification on recency, because outdated guidance floats around online. For most applicants, the 90 recent days must come from the seven years before you apply, under 46 CFR 11.201(c)(1). Our guide on how much sea time you need walks through common situations.
No. Recency means timing, not tonnage, for the licenses we teach. You need 90 days within the seven years before applying, and that time can come from the same kind of small vessels you used for the rest of your sea service.
Our breakdown of sea time requirements covers the edge cases.
A “day” has a specific federal meaning, and it isn’t sunrise to sunset. For a captain’s license, one day of sea service is eight hours of watch-standing or day-working, with a four-hour minimum on vessels under 100 gross tons. Credit is never given for stints under four hours.
The rule lives in 46 CFR 10.107, the definition of “day.” A calendar day counts once, no matter how many boats you were on. Eight hours on your boat plus eight on a friend’s boat the same day still counts as one day.
For its math, the Coast Guard treats one month as 30 days and one year as 360 days. If documenting all this feels fiddly, our piece on how to get sea time keeps it simple.
Your records are what the Coast Guard checks, and the form is the Small Vessel Sea Service Form (CG-719S). Document your captain’s license sea service on a CG-719S for each vessel, and back up any time on your own boat with proof of ownership. Fill out one form per vessel you served aboard.
If you owned the vessel, attach proof tying your name to the boat: title, state registration, Certificate of Documentation, an insurance card listing the vessel, or a bill of sale. Photos of a boat don’t count as ownership proof. If the boat belonged to a friend or family member, that owner signs the form to confirm your dates and role.
For time on a company vessel, the company signs off on official letterhead, and you can call the NMC at (888) 427-5662 with questions. One hard limit worth knowing: If the boat’s owner has passed away, you can’t claim that time, because the Coast Guard needs the owner’s verification.
The owner verifies it. You’ll complete a CG-719S that lists the vessel and your service, and the owner signs to confirm your dates, the role you filled, and the other details. That signature is what makes the time valid, so line it up before you apply.
Our sea time documentation guide shows what the signed form needs to include.
Some experience counts in ways that surprise people, and some doesn’t count at all. Military sea service counts toward a captain’s license at 60 percent of each qualifying day, while passenger time on a cruise ship earns no credit. The details decide which bucket your time lands in.
Military time has to match the kind of license you want, and a DD Form 214 alone usually won’t prove it. Bring an official sea service transcript, a certified history of assignments, or a certified statement of creditable service, and check with the NMC first. International boating experience can count toward a Merchant Mariner Credential (MMC) when you document it properly.
Crew or not, time aboard a cruise ship doesn’t qualify, because those vessels sit in a different class and you’re treated as a passenger. Veterans can also look at our American Hero pricing and our note on using military experience.
No sea time yet? You’ve got more paths than you might think. You can build your captain’s license sea service as a deckhand, on a friend’s or family member’s boat, on your own vessel, or through a local boating club.
The key is logging it as you go.
Hire on as a crew member or deckhand and you’ll rack up time handling lines, navigating, and standing lookout. Spend time aboard a friend’s or family member’s boat doing real duties, and have them sign off. Own a boat, and your time maintaining and operating it counts with proof of ownership.
Join a boating club, and you may find both boats and volunteer crew spots. Track the dates and hours from day one. Our guide on getting sea time without owning a boat covers each route.
A day is eight hours of watch-standing or day-working. On vessels under 100 gross tons, the Coast Guard credits a full day for four hours or more, per 46 CFR 10.107. Time under four hours earns no credit, and one calendar day counts once.
See our sea time documentation page for examples.
The 360 days never expire and carry over for future endorsements. What does have a clock is recency: 90 of your days have to fall within the three years before you apply. Keep getting on the water, and recency takes care of itself.
Our article on how much sea time you need explains how the two rules work together.
Sea time isn’t a hurdle the Coast Guard built to slow you down. It’s proof you can handle a boat and the people aboard it. Track your captain’s license sea service from your next outing, mind the three-year recency window, and the documentation stops being scary.
Start logging now and you’ll likely be closer to the 360 days than you expect.
If you have questions about sea service or any other part of the application process, the team at Mariners Learning System is here to help. We’ve guided more than 200,000 students through this process, and we’re not going to let paperwork be the reason you don’t get your license. Ready for the next step?
Start with our sea time documentation guide.
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