Many years ago I became an advanced open water diver. If you’ve never been scuba diving, it is the most peaceful, beautiful experience. It’s just you, the sound of your breathing, and all the wonders the ocean has to offer. Two of the reasons I chose to learn to dive are that I am claustrophobic and I am afraid of sharks. You’d think that a person with both these things would avoid diving, right? Yes, except that I cannot tolerate my choices being ruled by fear.

As it turned out, the claustrophobia wasn’t an issue for me because I didn’t feel confined in any way by the gear required for diving. The shark thing was another issue, though. I saw one, once. Now it seems funny, but it didn’t seem amusing then at all.

I was with two other people and we planned a simple dive near Humarock Beach in Massachusetts. The goal was to give us more practice and maybe catch a few lobsters for dinner. We swam out to the rocks where we planned to dive. One person dove down and two of us were still on the surface. My friend was having some difficulty letting herself sink. I was talking her through what she needed to do when I saw a very large dorsal fin about 100 feet behind her.