The thing you always come back to with a .22 are lightweight and is it backpackable. One i’ve been interested in for a while now is the Henry survival rifle. It breaks down, its light and it floats. Not totally waterproof but maybe with some silicone the leaks will be fixed. At least it won’t sink if it gets dropped overboard while i’m out kayaking.
The 9mm Masterpiece Arms option is very practical. Available as a pistol there’s a 16 inch upper that has a scope rail. Its one of the most adaptable guns ever produced. All kinds of parts and accessories. A really simple design. But I wouldn’t reload for it. Very good fmj ammo only, well crimped. The raccoons will scatter in every direction when the see it. House clearing gun. But might as well be a boat anchor for me. lol