I fell in love with Adventure Medical Kits when I first saw them hanging on a peg in Sport Chalet years ago; pouches of various sizes containing various medical and survival items designed to cover various specific situations and various amounts of people. At the time I was looking to put together such a kit myself for backcountry trout fishing when I saw AMK's ultralight model that would fit in the leg pocket of my cargo pants.
These days, Adventure Medical Kits have the bases covered with everything from monster kits for covering up to 18 people for 30 days, to personal pocket kits for one person, or even a dog. It was fun checking them all out while looking for one perfect for kayak fishing, and in the end, I settled on the Steelhead model in the Sportsman series.
The AMK Sportsman Steelhead weighs only six ounces and takes up about the same amount of space as a well-constructed pastrami sandwich. It was specifically designed for sportsmen operating under wet conditions, and it comes in both an exterior bag that is waterproof, and an inner bag containing that is basically a Navy-approved Ziploc bag on steroids. The stuff inside isn't going to get waterlogged, and the kit itself isn't going to sink to the bottom . It is designed for 1-to-2 people for 1-to-2 days. It pretty much has kayak fishing written all over it.
Inside you'll find an assortment of medical items catering to the most common injuries suffered by anglers; things like bandages, gauze, wound closure strips, elastic bandages with Velcro, and handy dope like aspirin, ibuprofen, antihistamines and antibiotic ointment. This is all ideal stuff to have around if you get cut by a bait knife, treble hook, gaff, or the pointy end of a barracuda.
With Adventure Medical Kits I like to take the contents to the next level by adding small items that fit in with everything else, but make the kit more tailored to my particular brand of outdoor experiences. Things I have added include a loud whistle (to say "here I am!"), sample-sized sunscreen, travel packs of additional ibuprofen (hey, if something happens out there where I need to slam some ibu just to get me through it, two is not going to do the trick!) and some tightly-wound parachute cord, because who doesn't love parachute cord?
Given the size, weight, affordability and waterproof properties of the Sportsman Steelhead from Adventure Medical Kits, there aren't really any reasons to not have one stowed somewhere on your 'yak or on your person.