gives a pretty good description of the types of OUPV licenses issued.
Its been my understanding that the USCG will consider time on your own boat. Since there is no way to prove the amount of time served on your own boat, and even attempting to contact previous captains would be difficult, they basically accept whatever you put down and swear as being true (not condoning fibbing here).
The form to use is here http://www.boatwise.com/pdf/719s.pdf
Dave in NC