How to Document Sea Time for a Captain's License

Sea time documentation is one of the most misunderstood steps in getting a USCG captain's license. The good news: most applicants already have qualifying time on the water — they just need to know how to record it correctly. This guide explains what counts as sea time, how much you need, and exactly how to document it on the Coast Guard's CG-719S form, even if you never kept a logbook.

Why Sea Time Documentation Is Required

The U.S. Coast Guard issues captain's licenses as endorsements on a Merchant Mariner Credential (MMC), and it requires documented sea service as proof of practical experience before granting one. This isn't a Coast Guard suggestion — it's a federal regulatory requirement. The rules for how sea service must be documented are set out in 46 CFR § 10.232, and the National Maritime Center (NMC) evaluates every application against them.

One important distinction: a captain's license course, like Sea School's OUPV course, prepares you for the licensing exam. Sea time is a separate, parallel requirement that you document and submit yourself as part of your MMC application. You can take the course and build your sea time documentation at the same time — but the Coast Guard will not issue your license until both boxes are checked.

How Much Sea Time Do You Need?

The answer depends on which license you're pursuing. The two most common starting points are the OUPV ("six-pack") license and the Master 25/50/100-ton license. For the full picture of every requirement beyond sea time, see our complete captain's license requirements checklist.

OUPV (Six-Pack) Sea Time Requirement

Under 46 CFR § 11.467, an OUPV license requires:

• 360 days of total sea service. Experience gained before age 16 is generally not creditable, so count your time from your 16th birthday forward.
• 90 days within the last 3 years. This is the Coast Guard's recency requirement (46 CFR § 11.201). If your qualifying service was on a uniformed-service vessel, the recency window extends to 7 years.
• 90 days on ocean or near coastal waters if you want a Near Coastal endorsement (valid up to 100 miles offshore). Without it, your license is restricted to inland waters.

Master 25/50/100-Ton Sea Time Requirement

• Near Coastal (46 CFR § 11.428): 720 days of total service, of which at least 360 days must be on ocean or near coastal waters. Inland service can substitute for up to 360 of the 720 days.
• Great Lakes and Inland (46 CFR § 11.455): 360 days of total service on any waters. To have your license cover the Great Lakes, 90 of those days must be on Great Lakes waters; otherwise it's limited to inland waters.
• The same 90-days-in-the-last-3-years recency requirement applies.

What Counts as a Day of Sea Time?

On vessels under 100 gross registered tons (GRT) — which covers nearly all recreational boats — the NMC counts a day of sea service as at least 4 hours underway in a single calendar day. The hours don't need to be continuous, but you can only claim one day per calendar day, no matter how many hours or how many boats you were on.

What counts is broader than many people assume. Recreational boating counts. Fishing trips count. Crewing on a friend's sailboat counts. Paid work as a deckhand, mate, or dive boat crew counts. Time on the Great Lakes, inland waterways, and coastal waters all counts — you'll just total ocean/near coastal days separately if you're pursuing a Near Coastal endorsement. Even military sea service counts: the Coast Guard typically credits 60 percent of your total time aboard as equivalent underway service (46 CFR § 10.232(d)).

What Form Do You Use to Document Sea Time?

The CG-719S — Small Vessel Sea Service Form

For service on vessels under 200 GRT, the Coast Guard uses the CG-719S, Small Vessel Sea Service Form, available as a free download from the NMC website. Here's how to complete it:

1. Use one form per vessel. If you accumulated time on three boats, you'll submit three forms.
2. Enter the vessel details: vessel name, official number or state registration number, gross tonnage, length, and the waters you operated on. If you don't know your boat's exact tonnage, the form provides a simple formula to estimate it from length, width, and depth.
3. Record your underway days by month and year, to the best of your recollection. The form is a grid: for each month, enter the number of days you were underway at least 4 hours.
4. List your role (owner/operator, mate, deckhand) and the type of service.
5. Sign the certification. No official ship's logs, GPS records, or fuel receipts are required — the Coast Guard accepts your signed attestation, made under penalty of perjury.

Who Signs the CG-719S?

• Your own boat: You sign as the owner and attest to your own service. Attach proof of ownership — your state registration or USCG vessel documentation (46 CFR § 10.232(a)(4)).
• Someone else's boat: The vessel's owner signs your form. The owner does not need to hold a captain's license.
• Company or charter vessel: Your employer can sign the CG-719S or, more commonly, provide a sea service letter on official letterhead listing the vessel name and official number, gross tonnage, routes, your position and duties, and your dates of service.
• Military service: Submit an official transcript of sea service or history of assignments. A DD-214 alone is not acceptable evidence of sea service under 46 CFR § 10.232(d).

What If You Don't Have Records?

This is the step that stops most applicants — and it shouldn't. The Coast Guard does not require contemporaneous logbooks, receipts, or electronic records for small-vessel sea service. You're allowed to reconstruct your time from memory: think through your boating seasons, typical trips per month, and the vessels you used, then enter your best good-faith estimate of days per month on the CG-719S.

Accuracy still matters. The form is a federal declaration signed under penalty of perjury, so estimate conservatively and honestly. And going forward, keep a simple logbook — date, vessel, hours underway, waters — so your next application or renewal is effortless.

Common Sea Time Documentation Mistakes to Avoid

After nearly 50 years of helping applicants, Sea School's instructors see the same handful of errors derail applications:

• One form covering multiple vessels. The NMC requires a separate CG-719S for each boat.
• Counting short outings as full days. A day generally requires at least 4 hours underway on vessels under 100 GRT.
• Claiming two days for two trips in one calendar day. The maximum is one day per calendar day.
• Forgetting proof of ownership. If you're self-certifying time on your own boat, attach the registration or documentation.
• Submitting a DD-214 for military time. You need an official transcript of sea service, not just discharge paperwork.
• Missing the recency requirement. All the sea time in the world won't qualify you if none of it is recent — 90 days must fall within the last 3 years.

When Should You Start Documenting?

Start now — before you enroll in a course. You don't need all 360 days documented before your first day of class, but the sooner you map out your sea time, the smoother your NMC application will be. Reconstructing years of boating history takes longer than people expect, tracking down a former employer or boat owner for a signature takes longer still, and NMC processing can add weeks to months on top of that. Sea School advises every prospective student to begin the documentation process as early as possible — and our advisors will help you do it. For a full picture of the journey, read our step-by-step guide to getting a captain's license.

How Sea School Helps With Sea Time

Sea School's instructors don't just teach maritime rules — they've guided students through this exact paperwork since 1977, and today more than 7,500 students a year train with Sea School. Unlike online-only competitors, Sea School's advisors at locations across Florida, South Carolina, Alabama, and Louisiana can review your sea service situation in person and help you build a documentation strategy before you even start your course. Our instructors know what the NMC actually accepts, because they've seen thousands of applications succeed.

If you're uncertain whether your time qualifies — mixed recreational and commercial service, military time, gaps in recency — call us at 1-800-237-8663 or visit a location. Bring your boating history, and we'll help you sort it out. You can also browse our FAQ for quick answers.

Ready to get your captain's license? Sea School's USCG-approved courses have trained mariners since 1977, with more than 7,500 students a year. Browse our OUPV course, explore all courses, or find a location to talk through your sea time with an advisor before you enroll.

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