i would hate to be afraid of deep water, some of the best times of my life have been while i was water skiing or wake boarding and being at the beach. sharks aren't to much of a worry, theres more people who die per year from falling coconuts.
I think it stems back from when i was kid some asshole was dunking me under water when i was about 6 and swallowed water was pretty sick for a day or two...Im talking about mostly deep sea like getting takin out by a rip or a boat tipping over...i think i have watched to many movies lol