It is not surprising that the oceans are an eternal object of myths and wonder. They never cease to amaze you, inspire you, take you by surprise.
Last night when we left the archipelago of Madeira the sea was flat like a pond, not a breeze stirred the evening air.
That was not meant to last very long; as soon as we left the protection of the islands (and the slightly elevated submarine topography between them - because not only what sticks out has an influence on things!) we got caught in quite some swell that lifted and dropped us all through the night and the best part of today.
In many a guest's mind the same questions are revolving, as they gaze out from the reeling into the far distance, across the horizon (or as they groan in their cabin, feeling queasy...): What makes these waves? Why are some so big and slow, some small and nervous? Why are they changing direction?
Well, it all begins with the wind. Somewhere, sometimes. Can be far away, can be long ago. A breeze parallel to the water's surface will create tiny little ripples that have a very short lifespan, maybe even under a second. But they add up, join, merge, building slightly bigger ones that can exist longer and start to propagate across the sea. And again they meet, causing interferences, sometimes getting bigger, sometimes eliminating each other. And here the cosmic rule applies: Big eats small, meaning that the wave's growth is a one-way street. Big waves stay big, easy as that.
And so they can travel literally from one end of the world to the other. These very old, slowly heaving waves are called swell. As we are traveling right in the middle of the Atlantic, it is nearly inevitable to have some of it. Ours today is coming from the west, America, that is. Long way to go, and we are just a cork on the water.
So, next time you look out at the sea - just remember that all of the big grandfather waves have started as minor little ripples, made by a wind that has stopped blowing long time ago.