Very deep water, unless I'm diving with a group of people. I just don't like getting into any body of water/oceans by myself. Hell if I can't see the bottom forget about it. It probably is because I over think things, thus causing me to overreact. However if I'm doing something on my boat and I have to get into the water to scrub the hull I can do that even though the water is like 25 feet deep and dark.
It's got to be the eels more than anything really.