Depth lost over about 15 knots

Bigplumbs

Bigplumbs

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On 2 of my boats where I have Garmin transom mounted transducers and garmin chart plotter combo and Striker 4 depth equipment. I loose the depth information (Depth just flashes and holds the last depth it had). when on the plane and over about 15 knots. Both these boats have outboards and I have mounted the transducers on the starboard (Right) side of the motor on the transom as the garmin instructions.

I was wondering if anyone else gets this and what a solution might be



Thanks



Dennis
 
jrudge said:
This is disturbed water flow that stops it working.

You need to either move it or if possible (unlikely ) remove the source of disturbance such as a hull fitting.
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The source of my disturbance is most likely the engine :). Don't think I can remove that. I don't have a huge amount of space that is the problem

Dennis
 
When I looked at fitting a fish finder/depth transducer I received advice that transom mount transducers can have this issue while a hull fitted transducer should be in n area of smoother water flow and is less likely to be affected.
 
Bigplumbs said:
On 2 of my boats where I have Garmin transom mounted transducers and garmin chart plotter combo and Striker 4 depth equipment. I loose the depth information (Depth just flashes and holds the last depth it had). when on the plane and over about 15 knots. Both these boats have outboards and I have mounted the transducers on the starboard (Right) side of the motor on the transom as the garmin instructions.

I was wondering if anyone else gets this and what a solution might be



Thanks



Dennis
Click to expand...

I gave up trying to get my transom mounted transducer to work at higher speeds and fitted a hull mounted one instead which worked perfectly.

Www.solocoastalsailing.co.uk
 
You can try a transducer shooting through the hull by sticking it as a temporary measure with blue tack or silicone.
When you find a good spot then fit a bath or bed in resin. The only thing to make sure is that there are no air bubbles trapped in whatever medium you use
 
In theory you can test with the transducer in a plastic bag of water held agsinst the hull floor though I never found this to be very practical .
Before OP tries that ..just try lowering the current set up and see if a cm or so lower is cleaner water.
 
If you elect not to go for a through hull you might want to try attaching the existing transducer to a broomstick or similar and get a crew member to move the transducer around [ edit: the back of the transom] a bit while on the plane until you find the sweet spot. For nothing else but to avoid numerous screw holes in the transom in a trial and error scenario
 
Last edited:
Had this problem on numerous boats over the years, fine tuning of the transducer position together with making sure it is well below the surface when the boat is cruising on the plane should sort it.
 
BruceK said:
If you elect not to go for a through hull you might want to try attaching the existing transducer to a broomstick or similar and get a crew member to move the transducer around [ edit: the back of the transom] a bit while on the plane until you find the sweet spot. For nothing else but to avoid numerous screw holes in the transom in a trial and error scenario
Click to expand...

I like the broomstick idea. Worth a try

Dennis
 
I have an Airmar P58 triducer mounted on the transom of my outboard powered Finnmaster, which is connected to my Raymarine A70D MFD, and I have no problems with the triducer reading the depth at any speed, even at the 34 knot max.

My triducer is mounted in a very similar position to your transducer.

The installation instructions for the P58 are as follows, which may be of interest:-

Mounting Location
CAUTION: Do not mount in an area of turbulence or bubbles: near water intake or discharge openings; or behind strakes, struts, fittings, or hull irregularities
CAUTION: Avoid mounting the multisensor where the boat may be supported during trailering, launching, hauling, or storage.
• For the best performance, the multisensor must be in contact with smooth water. To identify an area of “clean” water, observe the water flow off the transom while the boat is underway.
• Allow headroom space above the bracket for it to release and rotate the multisensor upward (see Figure 1).
• Mount the multisensor as close to the centerline (keel) of the boat as possible to ensure the sensor remains in the water when the boat is turning.
• Single drive boat—Mount at least 75mm (3") beyond the
swing radius of the propeller (see Figure 2). The starboard side where the propeller blades are moving downward is preferred.
 
So after reading many replies I have lowered the transducer on all three boats by about 8 mm and have rotated it to point forward more by one click. It actually looks much better now. We will see.
Thanks for all the advice

Dennis
 
Keep us posted please Bigplumbs! I have the same problem with garmin striker 5dv. Think it may be to close to the engine. Got any pics of what you have done?
 
wellf100 said:
Keep us posted please Bigplumbs! I have the same problem with garmin striker 5dv. Think it may be to close to the engine. Got any pics of what you have done?
Click to expand...

Now off for a week so will report back when I get home...... Going to go somewhere hot
 
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