On Mon, 20 Dec 2004 02:56:36 GMT, "Roger Long"
wrote:

The method for getting accurate wave height data from a boat is to know the
height above the waterline of some points at different heights. You then
stand on one and stretch or crouch until you find yourself looking across
the tops of the waves when the boat is in the trough. It usually takes a
few waves to get an average but it's quite striking when you get the right
position. You then measure from eye to feet and add it to the height known.
That's the average wave height.

I'm reassured. That's the approach I take when trying to make
estimates and I'm usually fairly consistent with what the Coast Guard
is broadcasting. I was wondering if you had some other secret trick.

I've often been amused to have even fairly experienced sailors say that the
waves must be eight feet. I usually don't point out that our eyes are
perhaps six feet above the surface and we can still see all the tops when we
are down in the trough.

Losing all the shoreside lights in the troughs can be quite dramatic,
and they are definitely higher off the water than the rest of the wave
crests.

Ryk