Depth Finder

[mrudman850]

My boat came with a Humminbird HDR 200 depth finder and in-hull transducer. The unit powers up and I'm able to set the alarm depth, but I get no depth reading. The transducer has been placed forward in the storage area at the aft end of the V-berth. It is not set in anything. How can I test, where and how should the transducer be installed?
Thanks
Mike in Plymouth
JULA
1977 #7575

 

[dziedzicmj]

You have to make sure that there is no wooden core where you install the transducer. If you have someone to help, an easy way is to put the transducer in a ziploc bag full of water, turn n the depth finder and move the bag along the bottom and check, where you get good readings. Once you figure out, where a good spot is, you can install the transducer more permanently, using a toilet bowl wax or, better yet, epoxy. Make sure, there are no bubbles (or air pockets), or it won't work.

good luck

 

[Drinkmilk]

I've been researching this too.

One vid recommended, while the boat is anchored/moored/stationary, hanging the transducer over the side in the water to get a baseline reading. Hold it at roughly the same depth as it will be when placed inside the hull. Then, as dz stated above, put the transducer in a ziplock bag of water and move it around the planned mounting area inside the hull to find the best/similar reading possible. Once you find the ideal spot, mark it and begin mounting.

Here's a mounting vid from YouTube. I just searched for 'Humminbird' and this was the 1st vid in the list.

Hope this helps. This is my very near future project too. Update us with pics and progress.

 

[mrudman850]

Thanks.....I'll give the ziplock bag trick a try this week.

 

[CaptDon01]

Your model might have plywood coring along the keelson, but even if it does, it doesn't extend to the V-berth area. Something else is the issue, bottom paint, barrier coating, bad transducer?

Good luck,

Don

 

[SFS]

I just reinstalled the Airmar P79 transducer for my Garmin 541s. The non-toxic antifreeze used as the transmission medium had apparently softened the silicone used in the original installation, and when I went to unscrew the transducer out of the mount to check the fluid level, the whole assembly came off the hull.

After doing some research, I would have used epoxy to reinstall, but had none available, and wanted to get it done that day. Instead I used some white Dow 795 I had leftover from replacing the acrylic in my hatches.

Make sure you follow installation instructions, which are likely available somewhere on the internet. There may be a specification that the unit be very close to level when finished, and the mount may let you account for a curved hull. Clean the area well with appropriate solvent to help with adhesion. Don't get epoxy or other sealant in the "transmission window" through which the transducer must send and receive signal. My instructions call for antifreeze as the liquid, but given the previous experience, I used mineral oil, as do many other folks.

I found the following link to be helpful in terms of ideas on epoxy to set the mount. This guy used two different kinds, one for adhering the mount to the hull, and a 5-minute version to form a "dam" inside the reservoir). If I ever have to reinstall again, I will go with epoxy, but for now, the thick bead of 795 I used seems to have squeezed out perfectly in both directions under the mounting ring, so I have a good seal on both the inside and the outside. Good luck.

http://themarineinstallersrant.blogspot.com/2014/08/p79-transducer-install-and-repair.html

 

[mrudman850]

Thanks SFS, my unit is of unknown age and came with the boat I purchased in November. She's now in the water. I'll experiment but something tells me the transducer might be bad.

 

[SFS]

See if you can find a model number on the transducer, or on a tag wrapped around the wire near the transducer. That may help with determining age and or installation requirements. Regardless, don't stress. Try the ziplock with water, up against the hull. That's a good first step. If you don't get a readout at the screen, then check that you have a good connection. I recently cleaned up all the tiny little pins and holes on my connector at the helm, using electrical contact cleaner and a toothbrush.

Don't be afraid to ask more questions here as you move forward.

 

[Jacktar]

put the shoot thru the hull transducer in the area under the forward storage compartment under the v berth not the area just in front of the keel box but just under the aft edge of the forward (sealed off from bilge) compartment near the center line, glob of toilet wax and you will be good to go for years.

 

[dziedzicmj]

If you think your transducer might be bad, do what Drinkmilk suggested - drop it into the water on the side. If it doe snot work there, it won't work in the hull. Eliminate one unknown at a time.

mdz