remote sensing

[mariner]

Given the controversy about LRLs, let me ask this: I have a probable shipwreck site on the Oregon coast where the wreck is buried 10 feet under a tidal mud flat. It is at the mouth of a river, but the water is sufficiently salty that the mud is impregnated with it.

The site is only some fifty feet off shore, and at negative tides you can walk across the mud flat and stand over the site. Alternatively you can stand on shore and have an unobstructed line to the wreck, which would only be some 60 feet away.

I used White's deep penetrating metal detector and got a strong signal, but this model does not discriminate between different types of metal. I think it possible that this wreck contains a substantial amount of silver bullion.

What is the best method of confirming the presence of silver and other possible materials on this wreck?

Thanks,

Mariner

 

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[old man]

Mariner,
This has nothing to do with remote sensing, but if you want a deep seeking detector that will tell you if the metal is ferrous or non-ferrous ?
Check out the pulse star ll, which is made in Germany. Kellyco in Florida sells them for around 2K. I've used them for over 15 years with good luck. If you buy one with the 40" coil, it is suppose to find a cannon buried 40 feet down. I have used one to find silver bars buried deeper then you are looking and it was in salt water.

 

[mariner]

Old Man,

Thanks for the info. I did not realise that there was a metal detector that would differentiate between metals that deep. I expect that this particular wreck was also carrying both bronze and iron cannons.

Mariner

 

[old man]

Mariner,
I think the unit is fantastic. The only problem is that the control box can not be taken underwater. You can purchase a 33 or 100 foot extension cable to take the search coil underwater to check out a site. The control box operator would have to remain top side. With the job you have at hand, I don't think you need any extension cables.

 

[stevemc]

I have a Pulse Star but it is not a II, and it is only a PI, it will not differentiate, as all PIs. Maybe the II has to be turned off and a magnetometer comes on. That will only tell you if you have iron or not. And it picks up from such a far distance, you really cant pinpoint if stuff is that deep. Mine will pick up a car from 30 feet or so, a beer can about 8 feet, in the air, and if it was in saltwater, it would go even farther. Yes to a certain point you can, but if it is like most wrecks, with pieces near each other, it will all be one big scream. Most old ship wrecks have lead or copper sheathing, bronze, iron or copper nails and spikes, iron anchors, bronze or iron cannons, iron cannon balls etc, so it would all be mixed up. Like SWR said, the only way to really find out is to dig down. I hope you know you cant really psychic the spot. Or hang a plumb bob. Or long range locator, as those really dont work. If they did, someone would have showed us by now.

 

[old man]

Stevemc,
Check the control box that you have, there should be 2 different colored lights. 1 green and 1 red, the red light shows that it is a non=ferrous target, the green means ferrous. The intensity meter will tell you how big or close to the target you are. I have used mine over wrecks and recieved both ferrous and non-ferrous readings. However, you are right. You have to dive the target or dig it up. Just because it says the target is non-ferrous, it doesn't mean you aren't digging up a beer can that I left behind.