Carabiners are incredibly useful for camping and kayaking. Carabiners range from non-load bearing versions for clipping on this-and-that, to heavy-duty, rated carabiners that can be used for rescue and climbing.
Use carabiners to clip drybags to your kayak deck or inside the hatch to prevent your gear sliding around in the hull. Secure your waterbottle, throwbag and bag of snacks. Around camp, use carabiners to string up washing lines, secure kayaks overnight and to hang water filters.
Rated carabiners, like those used for climbing, can be used for rescues, belays, and hauling kayaks up a cliff.