Aloha Idaho Ed,
Welcome aboard!! Good to have you here. Hope you can get the answers you need.
My opinion and advice to you is to contact local Maritime schools (probably Seattle
area) that do the licensing course for OUPV. Talk to them about how much their course costs. Usually about $1000. Then make the decision.
There are some correspondence type courses available and there are books
like "Get Your Captain's License" by Charlie Wing.
It is my experience that very few OUPV Captains gained their license by just gathering the material and then taking the exams. I could be wrong and there might be others on this forum that disagree but I think as far as time and effort goes you might be ahead by just taking the course and getting your license through one of the major schools in conjunction with the USCG.