In Iceland, you are able to snorkel not only between two tectonic plates but also in glacier water! It is some of the cleanest water in the world. So while you snorkel you can drink it, just like I did. It was very cold but during the time in the water we wore a dry suit (so no peeing in it like a regular wetsuit). I wore thermal leggings and a long sleeve shirt along with warm socks. It was not as cold as I thought it would be. The only thing in the water is your face. I definitely felt stinging at first then it went num which is totally normal. The guides kept letting us know it is okay for that to happen. The awesome dive company we went with was DIVE.IS. It was about a 30- 45 minute tour. It is more on the expensive side but where else in the world can you say you swam between the North American and Eurasian tectonic plates.