Depth sounder

[KB Gale]

I am a new boat owner of a 27' sloop that doesn't have a working knotmeter (though the impeller twirls freely), and doesn't have a depth sounder. I don't want to haul it out and put another hole in the hull for the depth sounder. Is there a depth sounder that would work through the hull? And what could be wrong with the knotmeter? Thanks

 

[wayne]

Depth and speed

KB If the impeller spins freely it must be the wiring back to the readout, what is the brand/make of the unit, and how old is the sloop?I strongly advise you get a depth sounder as soon as possibly, if you contact Raymarine they will tell you whats available and whether a hole through the hull is nessarsary. Its not nice sailing and not knowing how much water under the keel, enough to turn a sailor to drink. You also must know your boat speed, not only through the water but across the ground. Raymarine supply all this gear and its not that expensive.Good Luck

 

[Jim]

critters!

2 part answer....you don't say if the speed display lights up or if you get a speed reading when you do a finger twirl of the speed paddle wheel, but thats place one to look. If you do get lights and action, then how long has it been since your boat was hauled or the bottom scrubbed? Was there marine growth<critters> on the paddle wheel when you pulled it out? If so then there are probably worms, etc growing all around your speed transducer, interferring with the water flow. Regular bottom paint isn't good for the plastic on these things<or depthsounder plastic either>, and they often don't get painted with the special antifouling paint for plastics. Another problem I have seen is not inserting the transducer far enough when you put it back into the thruhull. Got to push a bit and make sure that baby is in far enough to do its job. Part two...There are at least a couple of companies that make depth transducers that can go through a hull, or that have explainations on how to set a transducer up for that. What they do is use something like mineral oil to help couple the transducer to the hull and conduct the sound waves from the inside. Do a Google.

 

[Jeff Powell]

Internal Transducer

I have had good luck installing the depth transducer internally on two boats. In one case a 6" dia. plastic pipe about 8" long was shaped to mate well with the hull with pipe roughly vertical. The hull to pipe joint was epoxied to make it leak tight. Place the transducer in the pipe and fill partially with anti-freeze. Fit a plastic cap with a hole for the cable and you are done.Looking for an easier way I simply applied a thin layer of silicon caulk to the transducer and stuck it to the flatest/thinnest section of hull I could find.Both installations worked well for many years.jeff

 

[jr]

stick your ducer in the toilet

I just took the advice of a past poster to use a toilet wax ring (no not a used one)to mount the ducer inside up near the bow. It works perfect, handles the hull angle easily and stays put. If you need to you can yank it off and try another location, cost 98 cents. Humminbird units can shoot thru the fiberglass without any problem. As a bonus I now have a small supply of sticky stuff should I ever need it.