Antibiotic ear drops. Tinactin or other antifungal cream. A broad-spectrum oral antibiotic. Nexcare waterproof bandages in various sizes (these things are incredible). Imodium. More bathing suits than you think are necessary (so there's always a dry/almost-dry one)--offset with fewer clothes that you think are necessary. Foam earplugs, if not something electronic (engine noise, anchor chains). Extra pair of glasses and sunglasses, if prescription, plus Croakies. A leash for your hat. Spare mask. Alcohol wipes/lens cleaners. A small dry bag with copies of passports, etc. (and a few days' prescription meds, if any) in case you have to evacuate. (More than 1 or 2 -- sorry)