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Whales and depthsounders

Teranodon

Member III
<style type="text/css">p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Helvetica Neue'}p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Helvetica Neue'; min-height: 14.0px}span.s1 {text-decoration: underline ; color: #dca10d}</style>I’m sure that I am not the only Puget Sound sailor who is very worried about the gradually declining population of “southern resident” orcas. The absolute number of whales had been stable for decades but, in recent years, the animals have stopped reproducing, which bodes badly.


Earlier this month, Governor Inslee’s task force released its final comprehensive report and recommendations. It is well worth reading. Acoustic interference from ships, ferries and boats is identified as the second most likely cause of the population decline (the first, of course, is lack of food). Among the sources of noise are depthsounders on recreational vessels, i.e., us. The offending frequencies are around 50kHz. I have a Raymarine P7 Shorty transponder on my E34, but I have been unable to find the frequency info by reading the manual, looking at the web site or contacting Raymarine directly. So I am thinking of implementing a simple mod to my suite of instruments. I could rig a switch that would de-power the depthsounder when the information isn’t needed. That, frankly, is most of the time. My chartplotter is a “virtual depthsounder”, and I could flip on the unit for entering an anchorage or when I am in a narrow channel. I happen to have a some spare wires running up the pedestal guard, so it would be easy to do. It probably isn’t going to Save the Whales, but it’s a small contribution that I can make.
 
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