I would suggest at the least a couple of disposable ponchos and some mylar blankets. They are cheap, not bulky and would do a lot to stop you from dying of exposure, which would be your greatest threat in a wilderness situation once you get on dry land. The mylars and ponchos could be completely submerged and still offer lifesaving insulation and protection from the elements. A small Esbit stove and a pot to cook in, add some dehydrated soups, cocoa or other hot beverages to warm your core from the inside as well as some high fat, high energy foods. Chocolate and Spam come to mind... Keep the furnace burning and keep the wind and water from chilling you and you may not be completely comfortable, but you will be alive