Join Date: Feb 2000
Location: Annapolis, Md
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Re: Installing Maretron wind instrument at the stern
First of all, I would disagree with the interpretation that Wikipedia's says that wind gradients only extend 2 meters. As any mainsail trimmer worth his salt can tell you, in light to moderate breezes and in thermal stratification conditions, the impact of wind gradient can extend well above the masthead. Even the article on Wikipedia aludes to this in their discussion of 'twist'.
But in my mind, the impact of wind gradient would not be the reason not to mount wind instruments down near deck level. The air flow around a boat is warped by the shape of the hull, house, rigging and etc. on all points of sail, not just upwind. Within that distortion are significant velocity (i.e speed and direction) changes that would alter the accuracy of the data obtained by the sensor to the point of making it meaningless at times, and if data can't be trusted, it is argueably not useful at any time.
Even masthead instruments are in part impacted by updraft off the sails, and by the air flow shifts around solid objects around the masthead. But this location experiences the least amount of induced flow changes which is why it is the typically selected location to mount wind sensors.
In terms of mounting new equipment, there are several options which may not require new wiring. Most wind instruments use four wires harnesses, and so you may be able to use your existing wiring harness but splice on new connectors for the updated equipment. (That is what I did.) You can also buy wireless wind instruments and from what I gather, these have a had good track record.
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Curmudgeon at Large- and rhinestone in the rough, sailing my Farr 11.6 on the Chesapeake Bay
Last edited by Jeff_H; 12-20-2012 at 08:47 AM.