Joke: I'm afraid for the calendar. Its days are numbered.
Fear: Thalassophobia: the fear of deep water, such as a deep lake, or the ocean, for example. I would suggest avoiding the ocean, lakes, and some rivers.
Fact: Jet Skis were first invented in the 1950s, though back then they weren't called Jet Skis, and weren't nearly as popular. Guess they needed to get the branding right. After all, the wrong branding, and people won't want to buy your skis. Instead they'll jet off.