CFR 46 -10 gives the requirements.
Electronic Code of Federal Regulations:
I can't see anything in the quals for OUPV that talks about the size of the vessel. I think you will need to have operated a motor of any kind..for the OUPV
Owners of vessels under 200 tons can document their own time.
You can also document time on other peoples vessels..just have them sign your sea service form....use the official one on the CG website.
It could take you several years to get to the 365 days....
Depending on where you want to charter out, you may need a near coastal license, otherwise if all your time is upon inland waters you'd be limited to inland waters, no more than 6 passengers.
I would call the CG, or one of the license schools to verify my arm chair guidance...