New member.. will the average metal detector work through 10-15' of water?

[trunkmonkey]

Howdy all, new member here from eastern South Dakota.

I'm thinking about trying to locate a knife I dropped down an ice fishing hole last winter, would a bounty hunter metal detector allow me to pick up a signal in about 10' of water? If not, what type of metal detector would I need to find an 8" steel Benchmade knife under the water?

 

[TABAGO]

I don't belive you will find a detector that will pick up any thing 10 feet deep! ordid you mean 10 in.

 

[trunkmonkey]

No it's 10 feet

 

[Ed in SoDak]

Hey, Trunkmonkey, welcome to a fellow South Dakotan! I'm on the opposite end of the state, though.

That's an interesting question you pose. Bounty Hunter doesn't make an underwater detector, but their coils are advertised as being waterproof. I don't know about how well-sealed they might be for 10 feet, I suppose you could add sealant to the outside seams and cable entry point.

Other manufacturers offer underwater machines, all of those made for an individual seeker are hand-held, so you'd be diving to reach 10 feet. Plus, they're relatively expensive.

I imagine an extender for the Bounty Hunter coil cable could be fabricated and you could attach the coil to a length of plastic plumbing pipe. But trying to determine where the coil was due to pipe flex and currents, then reading an iron knife versus any number of other iron items dropped over the years would be a major challenge.

Why not troll the general area with one of those super magnets or a magnet designed for just that purpose of retrieving lost underwater objects?

Unless it's a custom knife, some makers guarantee their products even against accidental loss and many makers and dealers work hard to maintain good customer loyalty. If you've been a repeat customer, it may not hurt to try.

Good luck!
-Ed

 

[Elton]

n/t

 

[mudpuppy]

Bummer! They make some nice stuff...If its 8" I assume its their fillet model? If so, its stainless most likely, and non-magnetic...we all lose knives every once in a while...unless you triangulated some shore line markings, you could actually snorkle down to it if the water is clear.
Mud

 

[trunkmonkey]

Wow, Awesome. I was born at RC Regional, it's live in the 6.0.5

Alright, those are some good ideas. I'll call Benchmade tomorrow, but im sure it won't be covered. I did try a magnet on the bottom of a 6x6 car speaker without any luck, I guess getting a stronger magnet might be the next best option. It's not the fillet knife(5000sbk), I say 8" because it was open when it fell.. the knife does have some sentimental meaning to me and retails for $260. It's not very far from shore.. maybe 30' and there is no motor boats allowed on the water. I am now on the hunt for a strong magnet and some thin rope.

 

[deliveryboy]

find an old hard drive or 2 and open them up there are earth magnets inside, very strong and maybe you can fish for it with that. I know harbor freight has some powerful magnets with a handle you can tie string to like this might work http://www.harborfreight.com/retrieving-magnet-250-lb-pull-36905.html

 

[Ed in SoDak]

A blade may be stainless, but in a folding knife, there's still the frame and springs, bolsters or other parts that are not likely to be stainless. Got anything similar in your collection to try a magnet on, wrapped in leather or electrical tape to avoid marking the knife?

I agree on the hard drive maggies. I pried a pair loose from a trashed drive and attach one to the belt clip of my Falcon so it's always there. The other clings to a spare digging trowel, so it stays with our detecting flat that's always in the truck even if no detectors came along.

Nothing intrinsically wrong with extending the cable from coil to machine, may even work at beyond 10 feet! Plastic pipe is quite flexible though. Wooden dowels inserted in the pipe may help, or you could use metal electrical conduit for most of the length with the stock plastic stem down near the coil. Tie and/or wrap a thin poly rope to the coil, so in the event you lose grip or the pole fails, the whole arrangement with coil attached doesn't join your knife down there swimming with the fishes!

I thought about attaching a magnet to the elongated stem somehow, thus that it could be suspended above the coil high enough to be out of detecting range, but easy to drop down to coil depth to "snag" whatever iron you may have located. That avoids a separate recovery effort once the detector locates a magnetic object.

I don't hold out much hope for a detector retrieval, but it's an interesting idea to ponder.

-Ed

 

[Bucksport]

Might I suggest something like this.
magnets
or this
more magnets

or the ultimate lift magnet
monster

 

[trunkmonkey]

You guys are awesome. At this point I am looking at the magnets from northern tool.. I found a store couple miles away. Im also scraping out a laptop.. I'm going to try and find one more hard-drive, rig up the magnets and start tossing.

 

[scampman_73]

might even try taking a clear plexi glass and attaching it to the end of a pvc tube so you can look at the bottom of the lake and spot it first. it might speed up the process by eliminating the need to fish for it blindly. just a thought. here's link to a nice underwater viewer. Good Luck!!

http://www.koiphen.com/forums/showthread.php?39402-Under-Water-Viewer

 

[trunkmonkey]

I dropped an underwater camera down the ice hole it went in.. I think it sank in the mud a little ways. I couldnt see it.