Can you swim while pregnant?

Obviously I know you can swim while pregnant. Holding my breath is what concerns me. I like to hold my breath and go under and “fetch” things at the bottom of the pool. it sounds weird but I get a ton of exercise doing this and I can do it for hours. I like to go lay on the bottom of the pool and forget the world exists for a few seconds. I just like to be under the water and sometimes probably for a minute at a time. Could I still do that?