Cruising Tropical Seas

Although not technically in the tropics, Anna Maria Island is close enough to have some tropical features. Many tropical plants grow here, and plenty of tropical storms come here. Many a tropical drink is enjoyed here! Sailing in warmer months certainly is a tropical experience. The friend who invites us to sail always offers the opportunity to cool off with the on-board spray, or with a swim in a pool back at the deck. It’s hot. It feels tropical.

The other day we were cruising Tampa Bay in a very stiff breeze. Gusts registered at 30 knots. We managed to eat our delicious Cuban sandwiches prepared by the ‘Havana Cabana’, despite the heeling of the boat and the tension on the reefed mainsail. We had left the jib down. Memorable as the sandwich and strong wind were, what struck me the most was the color of the water. It was such brilliant turquoise. I could not remember having seen it this color in recent sails. It made me feel as if we were in a tropical place. I wondered whether this is, indeed, the color of tropical seas. I wondered whether this always was the color of Tampa Bay, but I had just forgotten.

This led me to do a fair amount of reading on-line about the color of water. I confess that even after doing all this reading, I do not understand all the very complicated scientific explanations that were involved. These included discussions of the fact that the color of water is based on vibrations of molecules, and that some of the color is caused by reflection, refraction, and some of it is caused by absorption.

Cruising tropical Gulf of Mexico The simple fact that surprised me most, and which I was capable of understanding, was that water actually has an intrinsic blue color. I used to think the blue was entirely from reflection of the sky.

Proof that the color is intrinsic to the water can be seen by looking at water in an indoor pool with white sides and bottom. It looks blue. At least I think this is the case, based on what I read.