This is a great idea for keeping your vehicle keys safe during you're beach dive.
A small safe, with a combination lock, that is secured into your tow hitch.
Don't risk taking your key on the dive and donating it to Davy Jones' Locker. Leave that key securely on dry land!
Looking for a good price, they seem to be running $50-$100 online ($70 on Amazon right now).
On Amazon.com