Dinghy Depth Finder

[Parsons]

Do you have an electronic depth finder on your dinghy to help exploring for the big boat, or would such a thing be useful to you? I was watching one of the latest SV Delos videos, and it showed the crew exploring a poorly charted river using a handheld depth finder. Looked like a Hawkeye that you can pickup online for under $100. https://www.hawkeyeelectronics.com/handheld-depth-finder-w-temp/ I suppose for the fancier RIBs with electric start, you could get a permanently mounted one.
Do you think that such a thing would be useful, or do you rely on the "old lock tied to marked string" approach as a makeshift lead line? Are you never in a position of scoping out unknown anchorages or passage through the shallows.

 

[JimInPB]

Harbor Freight sells a little one that runs on AA batteries & has a tow behind transducer on a float for about $40. https://www.harborfreight.com/portable-fish-finder-62675.html

There were also some with very small transducers that have some kind of wifi type connection to a small display that you wear as a watch. I used to have one of those with the transducer on a spinning rod & the wristwatch display mounted to the rod, just above the reel seat. That way I could cast ahead of the boat & see what I was about to get into before I hit it. I see that they are now discontinued - https://www.amazon.com/Humminbird-Waterproof-Fishfinder-Discontinued-Manufacturer/dp/B0009PSA1M

 

[Charlie Jones s/v Tehani]

I've used a fishing rod, with a zebco. A weight that will sink he cork, a cork set just above draft of boat, and cast ahead- if it sinks, it's deep enough.

 

[capta]

Generally, I navigate by the color of the water and the surface action, even when using reliable charts. When neither of these things can be relied upon, I've used a 6-foot wooden oar with much success. Extending that on my arm I can reasonably assume that I've got at least 8 feet below the dink. No batteries to worry about and a positive depth.
Trying to avoid a hurricane in Fiji, I used this method and a couple of dozen bamboo stakes to mark a channel into a river that no one said we could get into. 180-knot storm and we were tucked in there snug as a bug in a rug.

 

[JamesG161]

We have a "Cajun Depth Finder" [Don't worry this was already cleared on SBO by Cajuns]



An old crescent wrench works well too.

Mark Twain...

 

[Captain Larry-DH]

I used to own a handheld depth finder and it sat on a shelf for years. When in Belize I took it along in the dinghy while we explored mangroves, I got a few readings and thought it was somewhat useful but not important info (no big deal if we ran the dinghy aground- just push off).

Imho it comes under the general heading of useful special-purpose tools/toys that are used sometimes or never, but nice to have if you can spare the space and don’t care about the expense.

I’m pretty sure mine fell into the trash by accident, it disappeared from my nav table one day and was never seen again.
No I wouldn’t buy one again.

 

[Kings Gambit]

At this point, I would never use one often enough to justify having to keep up w/the thing!

 

[MitchM]

we have the 1800's depth finder , a lead cylinder with a hollow end to contain the tallow to pick up dirt mud or sand from the bottom. it's been used twice in 40 years...

 

[Michael Davis]

Have a friend that has a depth sounder, chart plotter, computer and printer for his dinghy. We went to several uncharted areas while buddy- boating in 2017. There are a lot of places on the B.C. central coast that are as yet uncharted.

 

[RoyS]

Would like to find a "glass bottom" inflatable.

 

[Chris & Lenore]

I also (initially) wanted an easy to use depth sounder for our dinghy. I tried a few handheld models but they were a PITA ti use. I finally tried one of these Hummingbird portable units (see the pic) and like it the best. Easy to transport, easy transducer attachment and (important) non-slip case that stays where you put it.

But, after the novelty wore off - I rarely use it anymore...

Chris

 

[dlochner]

Would like to find a "glass bottom" inflatable.

These aren't glass bottom dinghies, but they might meet your needs:

https://www.defender.com/product3.jsp?path=-1|74081|801874&id=1778875

Or on Amazon: https://amzn.to/2Di0FJc

 

[JimInPB]

Would like to find a "glass bottom" inflatable.

Build one?
You can get sheets of 1/4" thick clear poly-carbonate from pretty much any plastic supplier & many industrial suppliers. A couple square feet of that, a tube of 5200, a handful of stainless machine screws with nyloc nuts & a few hand tools should be enough to get the job done, if you have an old low-speed tender that you are willing to sacrifice to the project.

 

[nat55]

How about a look bucket?
http://www.boatus.com/magazine/trailering/2014/october/how-to-make-a-look-bucket.asp

 

[jssailem]

How about stepping off the dingy and squishing your toes in the ooze... I guess we just have clearer water up here. You can tell if you are ashore or not.
Perhaps you guys are wanting to anchor in really shallow spots and the dingy is your exploring instrument. I am for sure not going to drive my boat into an area where the charts say Your going to get stuck! or the dinghy ride shows the bottom is just below the surface. So a dinghy depth sounder seems like an extravagance. I'd rather buy a good bottle of wine.

 

[Parsons]

Thanks for the feedback. @jssailem , must be nice to step off into ooze, not hard stuff!

 

[jssailem]

Yes. Squishy between your toes. But then up here there are the rock faces as well. These are sites that shoes work better.

 

[Michael Davis]

Step ashore here, neither squishy nor hard, chart says 600feet deep.

 

[Birdman737]

I've used my Hawkeye handheld depth sounder a bunch in Lake Huron's North Channel as well as Lake Superior's Isle Royale. So many anchorages in those places are not really charted (or horribly inaccurate), the water can be murky, and winds swirly, so I wanted a way to measure depth from the dinghy. I also occasionally use it to measure depth off the transom to avoid grounding the rudder in very tight anchorages (my boat's depth sounder is, like most, mounted forward of the keel). I also used it to survey my marina from the dinghy during low water years to avoid the shallow spots. It seems about as accurate as my boat's fixed depth sounder, and subject to some errors in weedy areas.