Are you doing this in a 22ft boat? That'll take some stones. I did the Ha-Ha in 2000, down, stay awhile, and back, about 60 days aboard, but the longest passage was only three days. I and a friend. Two others had dropped out at a late date. We found that underway, you only eat enough to fill the hole in your gut for right now. We survived mostly on peanut butter and instant hot cereals and instant coffee/tea. it was too much trouble to make up a meal every time, but we had one large, hearty hot meal a day, usually in the afternoon. Cooked in a pressure cooker, but not under pressure, it was a large pot with a locking lid. A can of chicken soup, a can of cooked chicken meat, a can of water, a cup or rice, simmered for twenty minutes, let sit for five, and bon apetit! Add spices and flavors to suit, mix it up with beef and rice soup, any way you like, the result is hot, tasty, and there's plenty of it. Don't even refrigerate leftovers, just leave in the pot, it will get eaten by whover is on watch later that night. Of course, we ate plenty of meals ashore, food is cheap in Mexico. (Don't go to the tourist joints, go inland for two or three blocks, eat where the locals eat) It worked for us, and we both lost about fifteen pounds in the sixty days and felt great.
As far as packing, two pair of long pants, six or seven pairs of shorts, several polo shirts (don't wear shorts and a T-shirt to any Mexican government office) some boat shoes, and pair of comfortable, sturdy walking shoes. Mexico is full of potholes, broken curbs, chunks of cement here and there, etc, with no yellow tape around anything. Keep your eyes and your mind open.
