It doesn't matter how many times I say buddy up there is always someone on a dive that doesn't follow the rules or gets lost in looking at something and the next thing you know they are without their buddy. I use this to signal the my family underwater and frankly when I am with my friends - this is a great way to get their attention when I want to share something special or let them know we are going up. This honestly should be on every dive, it is a lifesaver.