Extending length of coil cable for underwater search

[Alikhan]

Hello,
I have an old Garrett Master Hunter. It is not waterproof, but the search coil is. I need to do a search in fifteen to twenty feet of water, just to make a preliminary check to see if there is anything there. Is it possible to splice fifteen feet on to the wire/cable and drop the search coil into the water? The coil would have to be weighted. Would the coil's readings be picked up by the machine. Could this damage the machine. The splices in the wire/cable would have to be waterproofed. Once there is a reading, it is supposed to be something valuable, then a more professional search could be done with scuba and water proof detectors.
Thanks,
Alikhan

 

[Alan Applegate]

I question how well it would work. When they adjust the coils at the factory, the already have the cable attached. Since the cable does have inter-wire capacitance, I suspect the extra length would detune the coil assembly enough that is wouldn't work correctly.

 

[Sandman]

Garrett used to offer longer coil cables for what your talking about. I don't remember the length now but why not give them a call. It won't hurt the detector but could damage the coil if water got in the splice. You'd be better off just diving down there with a 1280 or CZ-21, something with disc. Lots of sinkers and such down there.