Depth finder

[Don]

anyone still reading this thread?

If so, two questions:1. Is there really and such thing as a KNOTMETER in-hull transducer?, and2. does anyone really use their depthsounder for anything other than confirming that, yes, we are aground?

 

[Tom]

To find the best location

for the sensor inside your boat, you can put the sensor inside a water-filled ziplock bag and investigate different spots. Its an efficient way to find the perfect spot with regard to the underlying fiberglass quality. Tom

 

[Terry Cox]

My manual advised me to partially fill a ...

Zip lock bag with water, remove any air bubbles then seal it. Lay the bag on the hull, rest the transducer on top of the bag and move it to different spots to determine the best reading.Terry

 

[Terry Cox]

Hi Don, they do make a knotmeter that does ...

not require a hole drilled in the hull. We use our depth meter to help locate the best place to drop anchor, to confirm chart depth information, location and underwater hazards. Terry

 

[jimq26]

Don - your answers -

1 - yes2 - yes

 

[tom]

jimq26 those units referenced use impellers!!!

Hey Jim I chased your reference and they mention protecting the impellers when hauling the boat on a trailer. If such knotmeters do exist I'd like to buy one. My impeller is always getting stuff stuck in it or growing on it. Barnacles seem to love the impeller blades and I have had a few grow in the area around the impeller. Theoretically I have read about speed sensors that use the magnetic field generated by moving water to determine speed/flowrate within a pipe.. This is for things like wastewater/sewage that would constantly foul an impeller. But if I remember correctly you must have a defined water stream with a reasonablly constant ion concentration. I guess the magnetic field depends upon the speed and the number of ions moving past a sensor.

 

[jimq26]

Yeppers - impeller driven.

Not like a paddle wheel though, this very small propeller rides on a fine rigid s/s wire. We have had no problem with weed or other fouling in the 4 years used. Don't know about barnacles (we're on the Great Lakes), but I've never had a problem with our local pest - zebra mussels.We generally use the knotmeter for racing since it reads to 1/10 of a knot. We can adjust the sail trim etc. and get every last ounce out of the breeze by watching the knotmeter. The GPS is not accurate enough for that job.

 

[gary]

use silicone

I installed my transducer using silicone caulking. It works very well. I cut the bottom of a paper cup out and taped the cup to the inside of the hull. I then filled it part way with a large blob of silicone on the hull and placed the transducer on it. The only caveat, which has been mentioned, is a cored hull.