I keep my own log of time on my boat and I "certify" my time on my own boat. For time on others vessels the owner needs to give a letter certifying the time YOU put on the sea time documentation Form that is provided in the application package. The time requirements vary with the level of license, for a 6pk you need 180 days of time (6-7 hours=1 day) for inland. I have the other days req. info at home if you need it!