Monday, June 06, 2011

The Sea State

New York Lower Harbor
40 30.28 N 073 59.72 W

I write often in this blog about the winds.  Of course the winds effects us first and foremost.  But the sea state, (i.e. the height, direction and period of the waves) also has a big influence.  I don't mention sea state often because it follows the wind.  The wind after all creates the sea state.  But there are exceptions.

Late yesterday afternoon, the wind kicked up nicely from the SE.  It was very welcome because we were weary of motoring and eager to sail.  However, for some reason, the sea also kicked up with 6 foot waves but from the NE direction.  That had two effects.

First, Libby appeared abruptly in the cockpit.  It took only one look at her green face to see why; she was seasick.  It has been several years since Libby has been seasick.  She uses Bonine pills and they seem to work.   Not this time.  She said that the nausea came on instantaneously as Tarwathie pitched and rocked in those darn seas.   She strapped on her electric shocking wristband and stayed in the cockpit and in a few minutes it passed.

Secondly, we couldn't sail.  Westsail 32s like to porpoise.  That means rocking, not side to side, but fore and aft.  The rocking and pitching are caused by the waves.  Worse, if the speeds are just right, we reach a resonance.   In a resonance condition, each Nth wave (N in the range 5 to 20) catches the downward pitching nose of the boat with such force that it nearly stops our forward motion.  Then, the speed builds again until N waves later.   With these SE winds and NE waves, and all our sails up, we would up in a miserable resonance.  I had to run the engine and add an extra 0.5 knots of speed to break the resonance.

Oh well, not to complain too much.  Within and hour the winds and the waves both disappeared and we were back to motoring on a flat surface.

Right now we anchored just north of Sandy Hook, NJ in the NY Harbor Lower Bay.   We'll enjoy a nap while we wait for the tide to turn.  Tonight, after dinner we'll have a sunset cruise through the Verazano Narrows and up to Manhattan at night.  The lights of the city at night can be really nice.  We'll probably anchor behind the Statue of Liberty and continue up river tomorrow.

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