Just going to put this out therem.. Its kind of gross though
if you REALLY don't wear a tampon and your flow is pretty light that day you can swim without it, and if a little blood gets in your bathing suit while yourre going back into the house to put aa pad on or whatever, bathing suits rinse out really really easily. Obviously, if its more than a little blood or a light coloured bathing suit it'll stain, but if your wearing like balck bottoms your don't have to worry aboutt like sprinting back into the house. You have a solid 5 minutes I'd say