we need more info....exactly which bit gets sore??? The cheeks, the fissure or other more intimate bits? My deceased aunt swore by Vick and mother by Vaseline as did Margaret Dye in her book on dinghy cruising. Perhaps the water in the heads is splashing up in the chop, and needs warming with the remains of the kettle ? The padded shorts could be the answer but depnds on whether or not you will welcome the attention that they may attract to that part of your anatomy !