Shallow water bottom finder

Reading posts and seeing pix of shredded mirage fins got me thinkin'... What if someone came up with a sacrificial wire extension attached to the fin(s) which would warn of bottom contact before the fins hit? Or, a wire attached below the bow which would also warn of submerged logs, for example? Something like the old 'curb finders' for cars should do the trick. It would be inexpensive, easy to replace and would extend the life of the fins. I thought about making a prototype but fear it would void the warranty. Anybody given it any thought? Maybe the Hobie folks?

Maybe a keel or dagger just ahead of the drive would work. Reallity... its not that big a deal unless you are going to be hitting logs and rocks on a regular basis.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Now that you have "published" you better get busy on your patent.
http://en.wikipedia.org/wiki/Curb_feeler

Whod'da thunk curb feelers would catch on?

I thought of that but a fixed keel or dagger would preclude really skinny water ops. I was thinking of encounters with oyster beds, for example, which could occur fairly often ... and hitting a submerged log or stump could do some damage to the drive, I would think.
Just a stiff but flexible wire 'bottom finder' would let you know to 'up fins' before impact.

Hobie can have the patent... just spell my name correctly on the check!

There's precedent for the idea ....
Fish with curb feelers

It doesn't like uplanned bottom strikes, either!

A lot of people fishing from kayaks are using through the hull Transponders for their fish finders. Most fish finders display depth information. I believe some of the better fish finders can be programmed to sound an alarm when going shallower than the defined depth.

True, but the minimum depth of the fishfinder is probably greater than the length of the fins. Humminbird, for example, has a minimum reliable depth of three feet; less than that and the fins could strike, but you won't know until they do. One could shift to paddle at that point, but that sort of negates the advantage of peddaling while fishing in shallow water.

Just go to "hover" mode of kicking the fins and you don't have that issue.. Any time you're in water that is questionable for depth, either slow way down with the cadence and be prepared to "pick em up" by feathering or hovering whichever you want to call it. Continue on. Proceed cautiously until in clear water. You can move forward and only be using a couple inches more than the hull draws if necessary. Practice that and you won't have near the opportunity to scar em up or break em. I'm in my 5th season on originals. I have some cuts on the fins, but they're still in use. Oyster bars and reefs, either man made or natural are an issue to be thinking about. In rivers, if you're nearing shallow water, obstructions, unknowns, slow down, feather em. If that doesn't do it for you, pull em out and proceed. I wouldn't let that deter me from having a Hobie. The advantages far outweigh the issue of banging em up.

_________________
Yakkingaway
Portsmouth, VA

Ebay has been selling though-hull transponders for about AUD50.00 (approx USD46 I think) and I've been thinking about getting one, but I have this nagging doubt about whether I could expect accurate or even close-to-accurate results.

The kind folks who sell them say they'll work through almost anything and 20mm of PE or OPP of my AI does not reduce their performance.

But I just don't know.............

Any opinions or experiences please?

I'm seeing more and more posts regarding fins damaged or lost ........ I tell ya', bottom finders/curb feelers are looking better all the time!

RPB wrote:

"Now that you have "published" you better get busy on your patent."

FYI, I've been hard at work on it! Here's what I've come up with.... now don't steal it!

I call this my Bottom Sensing/Collision Reference and Prevention System (BS/CRAPS)

(My old shaky hands won't allow me to do a sketch for you so you'll have to visualize this as you go.)

I duct taped a piece of an old busted fly rod to the very front of my yak, extending down below the depth of the fins with a comfortable margin of safety. (Lightly taped so it retains flexibility.) At the top, I stuck a golf tee through the center of a Lil Debbie miniature cherry pie pan (stiff aluminum foil - easy to work with and cherry is my favorite) and then down into the tip guide and taped it firmly to the rod. I then bent the side of the pie pan down into a notch which rests in the end of a piece of PVC pipe that runs down to the sail mount.

This is getting a bit more difficult to describe than it seemed... Let me just take you through the operation of the system, explaining the elements as I go.....

When the fly rod encounters the bottom or an obstacle, it wiggles and shakes a steel ball bearing off of the golf tee, into the pie pan and down the PVC pipe, making contact with two wires mounted in the pipe. This completes a circuit, powered by the fishfinder power supply and provides current through an ignition coil from a Model A Ford coupe to a set of contacts on the operators seat, causing the operator to rise abruptly. With pressure thus removed from the seat, a spring-loaded cord is released which pulls two ping-pong paddles, hinged one on either side of the boat, rapidly forward, thus arresting forward momentum and quickly imparting sternway to move the boat away from the potential collision. Because the rapid rearward acceleration could cause the operator, who is already in an awkward position at this point, to suffer whiplash and/or spinal vertebrae extension, a safety device consisting of a spring-mounted length of 2x4, mounted with a pivot on the center hatch, is provided. To protect the operator, upon rising from the seat, the release of seat pressure also releases the restraint holding the length of 2x4, which, by spring action, rises to catch the operator and prevent his continued forward motion.

Now, I realize that some improvements will probably be required but this systems will definitely give sufficient warning so that the operator can get 'fins up' before damaging them on either the bottom or a submerged obstacle, thereby solving a major problem, the severity of which can be deduced by the number of previous posts on this topic.

And they laughed at the Wright Brothers, who only made bicycles! Hah!