How to document sea time for your USCG captain's license — what counts as qualifying underway time, the CG-719S form, how to log recreational sea service, and how to avoid the documentation mistakes that delay NMC applications.
Not all time aboard a vessel counts toward your USCG sea service requirement. The USCG defines a qualifying sea service day as 4 or more hours underway — and only one day can be counted per calendar day regardless of total hours. Here is what qualifies and what does not.
The vessel must be actively moving on the water. Time docked, anchored (except during a passage), or hauled out does not count toward your sea service total, regardless of how many hours you spent aboard.
There is no minimum vessel size for most OUPV and Master 100 GRT applications. Kayaks and small dinghies are a gray area; anything with an engine or sails is generally accepted. Vessel type and tonnage matter for the tonnage endorsement, not for the basic sea service day count.
The USCG does not restrict sea service to salt water. Freshwater lakes, rivers, and the Great Lakes all qualify as long as the waters are subject to U.S. jurisdiction and match the route endorsement you are applying for.
You do not need to have been paid to operate a vessel. Recreational boating — fishing trips, day sails, cruising — all qualifies if it is properly documented. Many applicants build their 360 days entirely from recreational use.
The 90-day near-coastal sub-requirement (for near-coastal route endorsements) means at least 90 of your 360 days must be on near-coastal waters — bays, sounds, and ocean waters within 200 miles of a baseline. Inland-only applicants must show 90 days on their specific inland route instead.
What does NOT count: time docked or moored while the vessel is stationary, time at anchor during a layover (not during passage), time hauled out for maintenance, time as a passenger with no vessel duties, and time in a marina office or shoreside operation.
Requirements reflect total qualifying days. The near-coastal sub-requirement is a subset of the total — not in addition to it.
360 days
Route Sub-requirement
90 days on near-coastal waters
Notes
Inland OUPV: 90 days on the specific inland route. All 360 must be on waters subject to U.S. jurisdiction.
360 days
Route Sub-requirement
90 days on near-coastal waters
Notes
Same sea service as OUPV. Tonnage endorsement tied to actual vessels operated.
360 days
Route Sub-requirement
90 days on near-coastal waters
Notes
Additionally requires documented service on vessels of appropriate tonnage to support the endorsement route.
720 days
Route Sub-requirement
360 days on near-coastal waters
Notes
Higher service requirement reflects larger, more complex vessel operations.
All sea service must be on waters subject to U.S. jurisdiction. Days are calendar days — not 24-hour periods. One day maximum per calendar day.
The CG-719S (Sea Service Form) is the standard USCG form for documenting commercial sea service. It is signed by your employer, the vessel owner, or the master of the vessel — and it is the primary document the NMC uses to verify your sea service when you apply for a commercial license.
The form is available for download from the NMC website. One CG-719S is typically submitted per employer or per vessel, covering a specific service period. If you worked for multiple employers or on multiple vessels, you need a separate form for each.
Every field below is required. A CG-719S missing any of these will result in a deficiency letter from the NMC.
Vessel name
The documented or registered name of the vessel
Official number or state registration number
USCG documentation number if documented; state registration if not
Gross tonnage
Required for tonnage endorsements; critical for Master 100 GRT applications
Route operated
Inland, near coastal, offshore, Great Lakes — must match the route on the endorsement you are applying for
Dates of service
Start date and end date of the service period covered by this letter
Capacity served
Your role: operator, mate, deckhand, master, etc.
Total days of sea service
The NMC counts days, not hours — although some letters include both
Signature of employer or vessel master
Must be signed by the employer, vessel owner, or the master of the vessel — not a co-worker or peer
The form must be signed by your employer, the vessel owner, or the master of the vessel. A co-worker, fellow deckhand, or someone who was not in a position of authority over the vessel cannot sign. If the signatory is the vessel owner and not the documented master, they should note that relationship on the form. For recreational trips on a friend's boat, the boat owner is the appropriate signer.
Recreational sea time counts toward your USCG sea service requirement — but it requires different documentation than commercial service because there is no employer relationship. The USCG provides two acceptable methods.
A personal logbook is the most common method for recreational sea time. Entries must be contemporaneous (written at the time of the trip) and must include all required information for each entry. A logbook can be a bound paper journal, a printed form, or a dedicated nautical logbook — whatever you write in consistently.
Each entry must include:
If you cannot obtain a signed CG-719S from a vessel owner (for example, if you borrowed a boat from someone who has since moved), you may submit a signed statement from two witnesses who can attest to your sea service. Both witnesses must have direct personal knowledge of your service on the vessel — not hearsay.
The witness statement must describe the vessel, the waters, the approximate dates of service, your capacity, and the approximate total days of service witnessed. Each witness signs under penalty of false statements. This method is accepted but puts you at greater risk of an NMC deficiency if witnesses are not specific enough.
Six habits that make your logbook NMC-ready from day one.
Record every trip the same day
Write your entry the same day as the trip. Contemporaneous entries carry far more weight with the NMC than reconstructed logs written weeks later. If questioned, a logbook with consistent daily handwriting is much more credible than one that appears to have been filled in all at once.
Include exact start and end times
Record departure time and arrival time for every underway leg. This lets you establish the 4-hour minimum clearly and demonstrates exactness. Round trip: note time out and time back in.
Note vessel name, length, and type
Record the full vessel name, hull type (powerboat, sailboat, etc.), and approximate length or gross tonnage. For tonnage endorsements, you need to show service on appropriate-size vessels — this requires vessel-specific records.
Identify the waters navigated
Specify whether you were on inland waters, near-coastal waters, or offshore. Use recognizable geographic identifiers: 'Long Island Sound near coastal,' 'Mississippi River inland,' 'Gulf of Mexico offshore.' This directly supports your route endorsement.
Record your capacity aboard
Note your role on the vessel: master, operator, mate, crew, observer. Capacity matters — operating the vessel counts differently than being a passenger. Even time as a deckhand counts for sea service days under most circumstances.
Keep physical and digital copies
Photograph every page of your physical logbook and back up the images. Logbooks get lost, damaged, or left on vessels. The NMC will not grant an exception because your only copy was on a boat that sank. A Google Drive folder with timestamped photos of each page is cheap insurance.
Arriving at the dock, performing safety checks, and casting off does not count until the vessel is underway. Many applicants overcount by including time aboard at the marina. The 4-hour minimum is 4 hours of actual underway time.
The official USCG documentation number (for documented vessels) or state registration number is a required field. Letters that leave this blank are deficient and will trigger a deficiency letter from the NMC. Ask the vessel owner or operator to fill in the number — they will have it in the documentation paperwork.
The form must be signed by your employer, the vessel owner, or the vessel master — not by a fellow deckhand or a manager who was not on the vessel. If the signatory's relationship to the vessel is unclear, the NMC may issue a deficiency.
The 90-day near-coastal sub-requirement is tracked independently of your total 360-day count. If your CG-719S forms do not identify the route operated, the NMC cannot credit those days toward the near-coastal minimum. Always specify the route on every form.
Vessel owners, employers, and witnesses are exponentially harder to track down years after the fact. Employers close, vessels are sold, people move. Get your CG-719S signed at the end of each season — not when you finally decide to apply.
When to document versus when to apply — and why the gap between them matters.
Day 1
Start documenting — every trip
Each season
Collect CG-719S from employers
360 days
Apply for OUPV or Master 100 GRT
Sea time has no expiration date — qualifying trips from 10 years ago are still valid if documented. The documentation itself is what expires in practice: employers close, vessel owners become unreachable, and memories fade. Document contemporaneously and collect signatures every season.
Once you believe you have the required days, do a self-audit before submitting. Tally your total days, your near-coastal sub-days, and your days by vessel type. Confirm every CG-719S is complete and signed. Only then prepare your NMC application.
Sea time has no expiration date for NMC applications. Every qualifying trip you take today — and document properly — is available to you for any future license application, whether that is 2 years or 15 years from now.
At the end of each boating season, request a completed and signed CG-719S (or a sea service letter on letterhead) from every employer or vessel owner you worked with that year. Do not accumulate years of undocumented time.
Every deficiency letter from the NMC resets your place in the processing queue and adds weeks to your timeline. The single most effective way to get your license faster is to submit a 100% complete application the first time — and sea service documentation is the top source of deficiencies.
A qualifying sea service day is defined as 4 or more hours underway on a vessel — meaning the vessel is actually moving on the water, not tied to a dock or at anchor. Time spent aboard while the vessel is docked does not count, even if you are performing vessel duties. The 4-hour minimum applies per calendar day, and you can only count one sea service day per calendar day regardless of how many hours you were underway. Both saltwater and freshwater qualify, including the Great Lakes. Recreational boating counts if it is properly documented.
Yes. The USCG allows recreational sea time to be documented using a personal logbook rather than the CG-719S form, provided the logbook entries are sufficiently detailed: each entry must include the date, vessel name, vessel type and length, waters navigated (inland, near coastal, or offshore), duration underway, and the capacity in which you served. Alternatively, if you cannot get an employer to sign a CG-719S, you may submit a signed statement from two witnesses who can attest to your sea service. Logbooks should be kept contemporaneously — retroactive entries are harder to defend if the NMC questions them.
Start documenting from your very first qualifying trip — ideally before you even decide to pursue a license. Sea time has no expiration date for OUPV and Master license applications, so documented trips from years ago still count. The practical risk is that employers and vessel owners are much harder to track down after time passes, making it difficult to get properly completed CG-719S forms or witness statements. If you are starting fresh, keep a contemporaneous logbook from day one and request CG-719S documentation from each employer or vessel owner at the end of each season rather than waiting until application time.
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