$3000 for six months? easy.
first, get away from civilization. you spend money there. try the far out islands of the southern bahamas. fishing, conching and lobstering is more likely to support you there because of less fishing pressure.
second, stock the boat with staples. beans, rice, flour, powdered milk, etc. make sure it's all packed in sealable plastic containers. not too hard to take six months supply; if you need to buy more, staples are not as highly taxed as other foods in the bahamas so you can restock at reasonable cost. fruits and veggies may be hard to find and expensive there, so bring canned stuff. two 20lb bottles of propane
should easily last six months.
and when you finally have to return it's good to know it's a downwind sail to florida
i have a hunch that your boat is actually a glander tavana. if it is, i'm familiar with it, having spent years in the florida keys
near where they were built. they were nearly all 'kit' boats, bought as hulls and decks from glander and finished out by their owners. big advantage is the shoal draft centerboard
which will let you get into places in the bahamas where others can't - might be handy when a storm is coming.
which reminds me, get yourself some kind of radio
that will get you weather
reports. might just be an ordinary am radio
or better a grundig yachtboy or equivalent.
back in the 70's i met a couple on a bristol 27. they had spent six months in the bahamas and run out of money - living on beans and rice and lobster. he told me the last few weeks they were anchored in hopetown harbor over an old sunken boat; each morning he dove down and got a lobster for breakfast, then dove down and got a lobster for lunch, then dove down and got a lobster for dinner. then he said, 'you know, it's hard to believe, but you can get pretty sick of lobster'. i told him i'd like to find that out for myself...