As I hit the water after jumping off the boat in my full scuba kit, I have a sudden panic. Memory is a funny thing. It isn't till now that I recall my previous oceanic misadventures, one of which involved a family snorkeling trip in Hawaii when I was 15

> "How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" Sherlock Holmes, in Sir Arthur Conan Doyle's The Sign of the Four I’ve read about half of The Complete Sherlock Holmes collection of stories by Sir Arthur