Here’s a hypothetical. Let’s say, you’re about to do an Oly swim in a fairly warm water. You go for a pre-swim 15 mins before the start, and boom - you tear a huge gash along the seam. Your suit is suddenly filled with water everywhere. You still get the buoyancy, but it feels like you’re a giant swimming bubble at this point.
or you swim without. swimming in a wetsuit filling with water is like riding with a windbreaker on…parachute effect. if it’s just a teensy bit of water & it’s in there but not filling or moving (i.e. you’ve let water in but it’s not scooping water in with each stroke) it might be workable.
Depends where the tear is. Odds are you probably don’t have repair cement with you and wouldn’t be able to repair it in time even if you did. Better yet. Depending where the tear is…turn the wetsuit into a sleeveless or speed pants