The other night from a relatively deep sleep, I suddenly awakened. At the time, not realizing why, I left the berth and entered the cockpit to find that the boat had changed tacks, had changed its angle relative to the prevailing wind/wave such that instead of the wind coming over my side it was now coming over my back. 'Alright', I thought, and after admonishing the failed autopilot and putting Shearwater back on track, went back to sleep.

Later upon further reflection, I wondered what had in fact awakened me? Something had beckoned me, had broken some consistency in my mind upon which I relied for peace of mind and hence sleep - but what was it?

And then, in an instant and as suddenly as I had awakened that night, I realized what it was. It was a change in two things. One, it was the change in the undulations of the boat - ie waves hitting the side and waves hitting the back yield a totally different motion.

But, and more interestingly, it was an utter and dramatic change in sound. With wind and waves coming across your side, there is a sound associated with that - rather sharp and hard. When you change that wind/wave angle to coming over your back, (the wind/wave/boat now are all going in the same direction) the meeting is more gentle and hence a totally different sound. Having been a orchestral conductor most of my life, I was always in training to sharpen my perception of sound - to hear changes in the orchestral texture at any given moment and to correct modify or encourage those changes. Or, to put it another way, any change in sound from what I was expecting needed quick and immediate attention.

Here too aboard a boat, when one goes into a sleep, one leaves a window open through which comes a particular and expected sound associated with a particular wind and wave direction relative to the boat. Any change in that relativity, any change in that 'sound of sail' and one is alerted and awakened.

Example: 1. Sounds with wind and waves coming onto the side of the boat: short, loud and sharp, staccato. 2. Sounds with wind and waves coming onto the back of the boat: smooth, quiet and legato.

It was this change from staccato to legato that awakened me that night.