Artifact hunting

[Cave Diver]

I'm not really sure what forum this should be posted in, but considering some of the answers are likely to be technical in nature, I'll start here.

I don't have a lot of specifics, but I am still going to try to get some answers on the best way to proceed.

This starts off as one of those typical 'friend of a friend stories.'

Someone told a buddy of mine that their are some naval anchors lost in our local river. All that is known is a generalized location (could cover several miles of territory) an approximate depth (30') 'fast moving water' (knowing our local river, I doubt that rate would exceed 3-5 knots) and that there are two anchors; one has cable attached to it, the other has chain (possibly as much as a hundred feet or so).

My question is this: Does anyone have experience trying to locate an object like this? If so, what is the best way to accomplish it?

Here are speculations on our part:

• anchors are probably around 7' and weigh a couple of thousand pounds
• the river bottom composition is mostly mud and mud/sand
• visibility will likely be measured in inches
• unless they were lost in the last 6 months (highly unlikely) they are already below the mudline
• magnometers are prolly too $$$$ for our budget
• grappling will likely produce a ton of tree stumps and other debris

Given this scenario, how would you go about locating something like this?

 

[MichgnTechDiver]

Hmmmmm tough question. If you really want to find it, use an underwater metal detector. Thats the only answer i can find. You can easily find them for under $1000 and probably could find them on ebay cheaper. Plus, you can use them for much more than just these anchors......can we say pirate treasure!! lol

 

[MichgnTechDiver]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=1300&item=1983774456

Also, just out of curiosity, what river is it?

 

[Cave Diver]

MichgnTechDiver once bubbled...
Thats the only answer i can find.

That idea has been discussed and disgarded already. Sorry for not mentioning that. The reason is that we do not have an exact location, and with miles of river to sweep, this type of detector would be extremely time consuming. Also, from what I have been told, they are only have an effective range of about 20'', and it is possible these items could be covered by a thicker layer of mud than that.

Thanks for the idea tho.

 

[joens]

MichgnTechDiver once bubbled...
Also, just out of curiosity, what river is it?

nice try , you think he will tell you where it is.
joens

 

[100days-a-year]

With a good color bottom machine it is possible to determine the approximate density of objects on and in the bottom.It is atrial&error method.1st set the scale to over 2ce the depth of the river,turn up the gain until you get a second echo.This will show up as a second line at double the known depth.In the first echo a hard return (dark in B&W,red in color)will be a dense object.The relative densities can be tested over a period of time on known objects until you can "read" the difference.I hunt fossils in rivers composed of mud,shell and sand bottoms which have a low density and occurence of fossils and limestone which is dense and a higher percentage of fossils.I can read thru several feet of mud and a foot of sand.good luck.

 

[MASS-Diver]

Sounds like a tough search, 3-5knots is a prtty tough current as well.

I would say try to narrow down your search area, several miles is a huge area. Bribbing local fisherman, historians or whoever with beer is always a good call. Then , if you really can't get a mag (that's the only "good" way to look for something like this), I'd run over the target area with a good fish finder looking for anything that looks funny, with practice you should be able (at the least) to disguish between sunken trees and metal. That method would rely on lots of time and lots of luck.

Bottom line: get a mag or get a little tighter search area.

Good luck

 

[WYDT]

Cave Diver once bubbled...
Given this scenario, how would you go about locating something like this?

Just wondering but why would you want to try to find these? Are they worth a LOT of money?

You should weigh the risk vs reward here. Unless those anchors are made of gold I'd forget about the idea. It doesn't sound like you have any experience in salvaging this type of thing and something that weights thousands of pounds in swift water is nothing to play around with. Add in 0 vis and other debris and it sounds like a great place to die... hmm, come to think of it even IF those anchors were made of gold I'd leave them where they were!

Maybe I'm way off base here but this just doesn't sound like a good idea.

Dive SAFE and Often!

 

[Cave Diver]

WYDT once bubbled...
Just wondering but why would you want to try to find these? Are they worth a LOT of money?

Mostly just the challenge in it at the moment. I have not talked directly to the person who is supposed to know the whereabouts of them, so the info I have is mostly conjecture. The current speed is not an absolute, it is just an extreme possibility depending on where they might be at. Should the current actually be that fast, I wouldn't even consider a dive there. However, I tend to think some of the details have been exagerated (tho not necessarily on purpose).

That is why the first thing would be is to determine a good way to find them if we are able to narrow a search area down from say, 2-3 miles of river to several hundred yards.

As far as the low vis and entanglement hazards, that is our 'normal' diving.

Regarding the experience in finding and salvaging them (if possible), several of the people who would be working on this have experience. However, the FINDING is the hard part at the moment as the things salvaged before where either at a known location, or insurance or some other company with deep pockets was footing the bill for a search operation. As it stands, this is just kind of a personal project among several close dive buddies, thus the need for more cost effective (tho possibly more time consuming) ways to approach it.

Thanks for all the input so far.

 

[WreckWriter]

Just come to Ft. Lauderdale, those things are all over the place here. They're really not worth much of anything.

Based on the criteria you've given (objects buried in mud in snag filled area), you're basically SOL without a mag or similar device.

Do the research first. Find out if they really exist and, if so, a better location if you can.

Tom