Lake

Does anyone here know a good swim diaper that I dont have to order or hace any good ideas on how to make one. Thanks in advance.

A good regular diaper will work fine underwater, it will just swell a bit.
Only other option is to do the pull up side mod on a pair of little swimmers.

Try searching for pocket diapers. If you remove the pocket padding, you will see a thin terry lining. This lining is able to hold just enough to catch any dribbling when you're on your way into or out of the water.

You can also keep the pad in at first (or put it in after getting out of the water) for sunbathing.

I just use a diaper under swim shorts.

Unless you are fecal Incontinent just wear your swim wear and get yourself into the pool or body of water as quick as you can. Urine incontinent folks just let it go since that chlorine in the pool will kill any bacteria in the urine just look at the pool bars in the southern US and Mexico where people are drinking swill and letting it go as they sit there. saying this in jest so do not beat me up for it.

Whats the side mod? And thanks for the response!