My snorkelling day was shared with four beginner scuba divers and their instructors. During our lunch break we were in four meters of calm water and one of the instructors came to the surface announcing he'd just touched the bottom without his air tank. So the challenge was thrown out there and we all had a go. My first attempt was close but not close enough. My ears hurt. They showed me how to equalise and then I had a second attempt. Yep. I touched the bottom. Pretty excited about that. flippers allowed but no bouancy vest.