What counts as a sea-service day
NMC's current sea-service guide defines a standard day as 8 hours of watchstanding or day-working in an assigned deck or engineering position, not passenger time. For vessels under 100 GRT, NMC may credit a full day for 4 or more hours when the vessel's operating schedule makes the 8-hour standard inappropriate; service under 4 hours receives no credit.
Do not assume a long day automatically gives extra credit. Time-and-a-half is limited to vessels and service letters that show an authorized two-watch system; ordinary overtime, recreational small-vessel days, and most under-100-GRT work are still credited as a single day.
Recreational vs commercial
Recreational sea time on your own boat counts — provided it is documented and signed by a witness who can attest to the dates and the operator role. Commercial time on a USCG-documented vessel can be verified by the owner or master.
CG-719S: the small-vessel sea-service form
Use CG-719S for service on vessels of less than 200 GRT. Complete one form per vessel, list the body of water, official or state registration number, vessel dimensions and gross tons, propulsion, capacity served, days by month and year, average hours underway, Great Lakes days, and days shoreward or seaward of the boundary line.
If you own the vessel, attach proof of ownership. If you do not own it, the owner, operator, master, licensed personnel, or another person with knowledge of the service must attest to the form. For vessels over 200 GRT, NMC expects certificates of discharge, official letters, service logs, or comparable documents rather than CG-719S.
The same form matters later if you renew on recent service: the USCG captain's license renewal forms guide explains where CG-719S fits in the 5-year renewal package.
Near-Coastal vs Inland time
OUPV Near-Coastal requires 12 months of vessel-operating experience, including at least 3 months on ocean or near-coastal waters. OUPV Inland requires 12 months of vessel-operating experience on inland waters. For any original national officer endorsement, 46 CFR 11.201(c) also requires at least 3 months of qualifying service on appropriate vessels within the 3 years immediately before you apply.
For oceans, near-coastal, or STCW endorsements, 46 CFR 11.211 credits Great Lakes service day-for-day up to the full requirement, while inland waters other than the Great Lakes may credit day-for-day for up to 50% of the total required service. Track Great Lakes, inland, ocean, and near-coastal days separately on your forms so the evaluator can apply those limits correctly.