I also have a fear of enclosed spaces. (I have done some confined-space rescue, but I did NOT like it one bit. Wanted to puke when I got out. I don't understand it, really. Have no fear of heights--have walked the edge of a four-story (why do I want to spell that 'storey'?) and it didn't bother me at all. Even the thought of going splat on the ground below was no big deal. But tell me I have to go into a cave or very tight culvert and I ain't a happy camper. Don't know why. I'll go, but I won't like it. Later, I may puke, but if I'm doing so in open space, hey, that's cool by me.