A repair kit is a must-have item in the gear of any kayaker, even moreso for anyone who paddles a skinboat. And it's useful for repairing more than just your kayak! Most of the items in the repair kit can also be used for other purposes, such as repairing a wetsuit or drysuit, sewing a button back on your shorts, attaching items to your PFD or your kayak, and so forth.
What's in my repair kit?
There are a number of other items that you could include, but many of those can be found lying around your campsite. E.g., before you apply epoxy to a fiberglass repair, or GOOP to a skin repair, you should sand the area to give the repair better adhesion. No sandpaper? A piece of wood and some beach sand works to rough up an area. Sprinkle sand on it and rub it down with the piece of wood.When putting your kit together, try to imagine what could go wrong and think of how you would go about fixing it. Think of multiple uses for the items you have and think light and small. I like to use a Sharpie to write the contents of the repair kit on the outside of the drybag.
Finally, keep the repair kit in a place where it is easily reached for yourself or for others. If the rest of your group hasn't spent as much time preparing for eventualities you may be the hero of the day!