There may be some sort of leasing/co-leasing agreement that involves what you are looking to do, maybe a boat broker??
I have seen people in the past looking for the exact same sort of thing.
I personally would start out with a smaller boat that I could afford, learn the waters in that area, be able to come and go without a scheduling conflict with another party. That's just me though, good luck in your search.
There is some great salt water fishing to be had in this general area, you should jump on some local party boats or charters. Even though I have a boat to use I still like to jump on a head boat every now and then, especially for cod, but that isn't really local until the middle of winter.
Also you might want to post up in the "fishing partner" section of this board, let people know where your from and what kind of fishing you want to do, and a little about yourself. Enjoy