Hellobee Boards

We just used regular diapers when DS was really little, especially for the beach. In a pool it's one thing - they're constantly submersed and you have to be really careful they don't contaminate the water with poop. Hence the need for the swim diaper. But at the beach we usually had more splashing and playing in really shallow water, and more in and out of the water. The diaper would balloon up and we'd just change it after a while. When he was really young I didn't really want him peeing all over the place, which was way more likely than a poop anyways.

Disposable over the swim diaper (for car rides, out of the pool playtime, etc.) is a good idea.

At the beach I don't worry too much (unless I'm expecting a poop) and either use a swim diaper as a precaution, or nothing if she's just recently pooped - DD2 is pretty good about telling us what she's going to do before it happens now that she's a bit older....when the girls were younger, if they'd already pooped, I used a reusable swim diaper - I feel like those contain small amounts of pee better than the disposable swim diapers.

Same as @ShootingStar. A swim diaper is really only necessary if they are submerged for a length of time, like in a pool. On the beach I just leave him in his regular diaper since he's really just playing in sand or splashing.