 Presuming there aren't enormous waves, if someone can't swim very well, should they ever go into a sea, say, over their chest, where the water might come over their chest? Well, that's a great question. Let's address it this way. With your group, when you guys are getting ready to go to a park, a pool, or the ocean, open water, assign a water watcher. Assign someone that knows everyone in the group, kind of do a little interview of how well they swim,