Jump to content

Depth sounder on small boat


Recommended Posts

I've been enjoying exploring some shallow inlets in my Spindrift, and wondering if I could add a depth sounder in some way.


I feel that the daggerboard is a bit vulnerable to a grounding and in some places the water is not clear enough to see the bottom. I think a simple sounder would make messing about in shallow places much more fun.


I don't want to reinvent the wheel so has anybody in here already done this? I can see three options:

- a self contained handheld unit, which my crew could operate. I don't think this would work at high speed and doesn't give a continuous reading. Also pretty useless when single handing unless I stop every time I want to check the depth.

- a battery operated unit with a transom mounted transducer. These mostly seem to be fish finders. Not sure how well these function as a pure sounder. And how well does a transom mounted transducer cope with the boat's wake?

- a proper built in unit with separate power supply. This option might work if I had a small 12v battery aboard to power nav lights as well, but that's starting to sound like a bigger project and potentially a lot of work.


Ideally, I'd want to fit the display on the forward bulkhead, but that's not ideal if I use a transom mounted transducer. And I don't think a through-hull transducer would work up in the bow section due to the vee shape. And would it work through plywood anyway?

Link to comment
Share on other sites

I have a cheap ($200) Humminbird fish finder and a removable transom mount for the transducer.  I also have a rechargeable motorcycle battery.  I’ve been meaning to try them out on Avocet, but always forget.  Maybe this post will be my incentive to try it out.  

Link to comment
Share on other sites

For decades my centerboard was my depth sounder. Then a few years ago we took our Core Sound 20 to the Columbia River, where there are 9ft tides. I bought a battery powered hummingbird with transducer mounted at the transom and the display also on the inside of the transom facing forward. It was an amazing improvement. It came in handy when transiting the shifting sand banks where charts aren't very accurate and I was surprised at how useful it was when anchoring. I was looking at it so much that I got tired of always looking backward while sailing or anchoring.

Then last year we went to Puget Sound where there are 15' tides. I upgraded to a full chart plotter with a transom mounted transducer and put the display under the mast step. Another fantastic improvement, but this was a lot more work to do because it takes about .5 amps while it is running, so it pushed me to add an electrical system to my boat (which has other advantages).

  • Like 1
Link to comment
Share on other sites

I have an Optima battery that I use on my Bay River Skiff, when I use my trolling motor.  But it is WAY too heavy for a Spindrift.  I also have a small motorcycle battery that I can use for small electronics and charging my phone.  That is what I’d suggest for a depth sounder on a Spindrift.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

By using this site, you agree to our Terms of Use.