"Go a mile find a wreck"

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munromh

Contributor
Messages
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Location
Mystic, Connecticut
# of dives
Hey all,

Some of you know that a group of us based out of Mystic Connecticut and Jamestown Rhode Island spend a great deal of time looking for, finding, and diving previously (un)explored shipwrecks. It’s just our passion: time on the water, good friends, the history, the hunt, the exhilaration of discovery, and excitement of diving a new wreck. I’m in the process of “modernizing” my web site and on the new site I’ll have a section where I’ll publish some of the fun we've been up to with New England shipwrecks. My hope is that the information we've accumulated can be more easily enjoyed by a wider base and not by just those directly involved. Until the new web site is fully up and running, the above link points to the old site, I plan on using this forum to accomplish that goal.

Go a Mile Find a Wreck

A good friend of mine and fervent supporter of my side scan sonar work, Larry Lawrence, has a catch phrase that recently proved itself twice in as many weeks, Go a mile find a wreck.

The first instance was while a group of us were on a scanning trip to East Hartford to image a schooner that recently came to our attention in the news, Police officer hoping to solve mystery of sunken schooner. After leaving the boat launch, and before imaging the schooner, I wanted to “play” around with the sonar and image the river bottom from bank to bank. Just at the beginning of our trek north I saw a promising target:


125 meter per side, 400 kHz, east bank on right, west bank on left.
Target 1, 11-08-2014. 400kHz, 20141108161424, Ping 1848a.jpg


After we finished imaging the river bottom from bank to bank we then focused our attention on the task at hand, imaging “The Schooner” (more on that later). This proved a challenging task due to the shallowness of the site and required a number of hours to accomplish. Time sure does fly when you’re having fun ……..

After we completed our primary task we continued down river to look for the “target of interest” that I had seen earlier. It didn't take long before we found what we were looking for ….. Just a third of a mile from the known schooner shipwreck.

50 meter range, 900 kHz, river flow from left(north) to right (south):
Target 1, 11-08-2014. 900kHz, 20141108180326, Ping 163434a.jpg

It looks to be a small 8’ x 30’ work barge of some sort.
One more item on the list to visually inspect someday, so much to do so little time ………..

15 meter range:
Target 1, 11-08-2014. 900kHz, 20141108180326, Ping 176505a.jpg

The second instance this past month which triggered the saying Go a mile find a wreck was while scanning shipwrecks off the shore of Bridgeport Connecticut with Tom Hajek on his dive boat Karma. We had just completed an in depth survey of one particular wreck and were transiting to another wreck when we stumbled across a previously uncharted wreck 1.2 nautical miles away.

Target 2, 10-25-2014. 900kHz, 20141025164310, Ping 59552a.jpg

I had the chance to dive on the wreck this past Tuesday and it’s a small coal barge. The only part of the barge left are the sturdy support timbers (floor timbers?) that made up the bottom of the barge, scattered anthracite pea coal, and one very large (broken) white glazed crock. Viz was terrible so I didn’t shoot any video/pictures. It looks just like the scan though, the bottom timbers are high and exposed at one end and disappear into the muddy bottom on the other end.

So there ya have it, Go a mile find a wreck! That’s one of the things which makes this so much fun, you just never know what you’re going to stumble across. Sometimes it can be hours or days of “mowing the lawn” with no reward while other times the sea gods smile very kindly on us.

Best regards,
Mark
 
I'd like to maybe do something like that downeast here in Penobscot Bay. What are the pros and cons of the side scan sonar you use?
 
What are the pros and cons of the side scan sonar you use?

The sonar I was using in this post is a friends system, an Edgetech 4125 dual frequency 400kHz/900kHz.

The one big con on this system is price, bought used they run about $35k. The pro on that price point is in sonar systems you typically get what you pay for so you can expect to get very good quality images. Quality in sonar is: low noise, resolution, range, and dynamic range.

On the pro side the system does make great images with the 900kHz on short range and the build quality of the system, from what I've seen, is good.

If you wanted to do something like this downeast then fortunately there are a lot of options available to you at various price points. You could start out with one of the depth sounder style options made by Humminbird, Lowrance, or Raymarine. They start in the $600 range and run up into a few thousand dollars. The one negative with this type system is that the transducer is mounted to the boat so the image quality will degrade the more the boat moves around. Also, the transducer is essentially at the surface so the deeper the water, the higher the transducer will be off the bottom, which means a lower effective range. That said my friend has a Humminbird unit and he mounted the transducer to a homemade PVC towfish to get it down in the water a bit and to decouple it from the boats movement.

The next step up would be to something like the Sportscan made by Imagenex. I believe they start around $5k new and you see them on Ebay for less. I have a friend who's been using one of these to find wrecks up in the Great Lakes for a long time. He's modified it a bit to work for him but it's obviously a viable system for what he's looking for.

As for finding wrecks or imaging wrecks with sonar, not one tool works in all situations. The size of the wreck, the age of the wreck, the bottom terrain, the depth, the area needed to search, and the time you have to do it dictates the capability of the system needed. Of course that's for finding a wreck, if what you want to do is produce quality detailed images of a wreck then the system requirements change again.

Hope that helps a bit. Let me know if I need to fill in any details.
Mark
 
I have a 2013 Edgetech 4125 also (400/900w/CHIRP & telemetry) and the unit is outstanding. In Lake Winnipesaukee alone here in N.H. I have found more than 70 wrecks, about 35 with a Humminbird 1197, and the rest with the 4125 in the last two years. Between the two systems I am having a great time and combine that with being a diver it's is a wonderful experience.

Some of my images are at www.sonasar.com

I am anxious to get the 4125 in the CT River north of you around Bellows Falls VT down to the Mass. border next summer. I've dived a lot in the CT River and used the HBird there but not the 4125 yet. Also want to get over the Mass. coast where I dive a lot too. Lots of great wrecks to scan.

Thanks for posting.
HH

---------- Post added November 15th, 2014 at 07:40 PM ----------

Correction to web address-left out an "R":
www.sonarsar.com
 
Thanks for the post Hans, very nice images on your site. Two things caught my attention:

If the nature and scope of your search/scanning requirement is beyond our capabilities we will gladly refer you to someone who can do what you need done.

I like an honest person who's not looking strictly at the $ but is interested in providing a quality service, even if that means passing on work.

Law Enforcement/SAR Personnel: We will provide services at no cost.

Bravo! That's a great service you're providing for free.

Mark

---------- Post added November 17th, 2014 at 10:34 AM ----------


I don't currently have a "depth sounder style SSS unit" on my boat but I'm thinking of getting one. After using the Lowrance unit on Tom's boat while hooking into the Bridgeport Barge, the one found in my initial post above, I can really see the utility of having one on board. If anyone has any comments on where to look at decent reviews on the various units currently available I'd be interested.

Mark
 
Thanks for the post Hans, very nice images on your site. Two things caught my attention:
If the nature and scope of your search/scanning requirement is beyond our capabilities we will gladly refer you to someone who can do what you need done.

I like an honest person who's not looking strictly at the $ but is interested in providing a quality service, even if that means passing on work.

Law Enforcement/SAR Personnel: We will provide services at no cost.

Bravo! That's a great service you're providing for free.

Mark

---------- Post added November 17th, 2014 at 10:34 AM ----------


I don't currently have a "depth sounder style SSS unit" on my boat but I'm thinking of getting one. After using the Lowrance unit on Tom's boat while hooking into the Bridgeport Barge, the one found in my initial post above, I can really see the utility of having one on board. If anyone has any comments on where to look at decent reviews on the various units currently available I'd be interested.

Mark


Mark the Humminbird 1197 I bought new in 2009; Since then it has been phased out by HBird for other similar units; For both cost (don't want to spend more money) and function reasons (I really need it and it works great) I am keeping it thus I can't suggest what HBird unit someone buys if they were to do so today because I haven't looked.

That said it would be a smart move to look at Lowrance and Raymarine units as well.

I use both the Edgetech and HBird all the time depending on what I am doing, where I am doing it and a host of other variables. While the Edgetech does have a GPS integrated Coverage Mapper function built-in (no chartplotter per se displaying an actual nautical chart or similar map) I actually use the powerful chartplotter function of the HBird with a Navionics chip to run my scan lines using the bread crumb trail feature-works like a charm.

Using the HBird for plotting and running lines also frees up more real estate on the Edgetech laptop screen. You need a chartplotter function regardless of what you are doing-scanning or diving.

Two popular private HBird sites are:

Unofficial Humminbird Side Image Forums www.sideimageforums.com - Index page

http://sideimagingsoft.com

Just about anything you'd want to know about Humminbird "side imaging" units is at these two sites; I would imagine there are similar sites for Lowrance and Raymarine so folks will have to Google for them.

Suggestions:
1) Shop whatever you buy around as much as you can;

2) Proper installation-especially of the transducer, is critical; Never cut the cable to get rid of it "extra cabling"-leave the full length of the cable from the Unit to Ducer intact; I had someone install the whole trip for me and it was worth it;

3) Buy the biggest screen size you can get; Many people buy the smaller windowed units and regret it; Spend the money and get the biggest unit offered, whatever brand you choose, and you won't be disappointed.

Any hull-mounted system in the hands of a skilled operator will produce results you will be impressed with. While it's no towed system-not even in the same solar system of capabilities, it doesn't even need deployment as you just turn it on and start scanning. You can go in super shallow water, take advantage of multiple frequencies, capture images and video of the scan and much more. But it has some big drawbacks as you mentioned including having the Ducer at the surface not near the bottom, wave action beating your images to death, lack of power needed to go long distances and more.

But I would never have a boat without one.

Hope it helps.
Hans
 
Hey all,

I wanted to follow up on my original post with information on the reason I was on the Connecticut River off East Hartford when I found one of the shipwrecks mentioned above. The day we found the little work barge my friends and I had set out to scan the schooner off Great River Park in East Hartford that was mentioned in this article: Police officer hoping to solve mystery of sunken schooner.

Well, I've finally updated my web site and I added a Blog section which I hope to update at least once a month. You can access the Blog entry on the schooner from the main page or go directly to it from here.

Before you go you can enjoy a little "appetizer" video to whet your appetite:

[video=vimeo;117716396]http://vimeo.com/117716396[/video]​
 
https://www.shearwater.com/products/peregrine/

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