I went to Scotland 11th-15h April 2012 with Maria, Julia and Linda. Before we went I joked (with a very slight element of seriousness) that we should take our bikinis and swim in Loch Ness. We had a look on Youtube and actually found some videos of people doing it, so we decided we would.
We arrived in Loch Ness, but most of the Loch is fenced off and we wanted to find somewhere relatively private to swim. It was long walk all the way round and we had to take an 'informal' route through a forest (walking across logs and through streams) to get to the actual lake. Just before we went in, it started hailing. As it was April, it was quite cold. We reckon the temperature of the lake was about +6. Nevertheless, we ran into the lake in our bikinis, screamed at the feeling of the temperature and ran back out. I floated for a few seconds, so you could call it swimming. I actually fell on some rocks and the way out and cut my leg open, so there were some pretty bad scars on my legs for quite some time. We pretended it was the Loch Ness monster.