Sea service experience is measured in eight-hour calendar days where any day that you are on a boat of any type or size for four-hours or more is counted as one eight-hour day. None commercial sea service experience is never credited for more than one day for each calendar day regardless of the number of hours. Sea service experience is counted as either inland or ocean experience. If the entire day was spent on waters shoreward of the boundary line (a line drawn between the end of the jetties or most seaward points of land) then that day is counted as an inland sea day, but if at any time during the day you sailed beyond the boundary line into ocean waters that entire day is considered an ocean sea day.
To document sea service experience on vessels of less than 200 tons use the small boat sea service form CG 719S. Use one form for each vessel you are claiming sea service experience on. The owner, operator, or master of the vessel must sign the form; if it is on a boat that you owned then you will need to provide proof of ownership. The USCG will only accept government issued ownership such as copies of documentation or state registration papers.
Providing documentation of sea service can be difficult for vessels where the owner, operator and master are deceased or for small non-power driven vessel that you owned that were not documented or state registered. You could attempt to provide testimony from relatives, but my experience is that the USCG is slow to except anything outside the norm when it comes to the application process or documenting sea service.
