Edmund Fitzgerald side scan images

[Jared0425]

Nice sidescan images. Looks like the sea state (lake state) wasn't perfectly flat (as there is some distortion), but a very nice image nonetheless.

The bottom terrain is caused by the actual wreck itself. The ship is missing approx 250-320ft of her hull, so a theory being is that it is obliterated and lying in pieces on the bottom. In a zone of about 8 miles is completely flat. The wreck of the Aurania is not too far away and she sits completely flat on the bottom. There is a depression 500 yards away (not shown nor relatively known).

 

[JohnN]

From Wikipedia: ". . . Fitzgerald suddenly sank in Canadian waters 530 feet (160 m) deep, approximately 17 miles (15 nautical miles; 27 kilometers) from the entrance to Whitefish Bay. . ."

That would be a seriously deep dive. I was under the impression that the limit for recreational tri-mix was 330 feet. . .

 

[Dhboner]

Ironically, we dive the Brunswick, Carlingford, Dean Richmond, John J. Boland, etc., etc., etc. (the list goes on, and on, and on), all which claimed lives in their sinking....

So, why the "double standard"?

I'm not sure why some wreck sites are protected and others are not. My post was just meant to encourage you to think beyond the Canada versus U.S. approach. They are the remains of American merchant seamen on that wreck. The Government of Ontario simply wants to restrict diving on her out of respect for the families. Personally I don't have a problem being prevented from diving any wreck where human remains might still be found...at least not recreational diving. If there is a good reason e.g. attempting to determine the cause of the tragedy then that is an entirely different story.

I don't mean to argue with you I just have strong feelings about what a shipwreck at the bottom of a lake/ocean means to the families of the crew who may have died.

Bob

 

[Cave Diver]

From Wikipedia: ". . .Fitzgerald suddenly sank in Canadian waters 530 feet (160 m) deep, approximately 17 miles (15 nautical miles; 27 kilometers) from the entrance to Whitefish Bay. . ."

That would be a seriously deep dive. I was under the impression that the limit for recreational tri-mix was 330 feet. . .

If you look, you'll see a post made here on SB about some of our members who recently completed a dive beyond the 600' mark.

Edit - Link: http://www.scubaboard.com/forums/tek-trip-reports/422349-add-helium-dive-team-completes-dive-652-feet.html

 

[ComputerJoe]

I'm not sure why some wreck sites are protected and others are not

One theory is that the mis-charting of Caribou Shoal would carry no small amount of government liability if it was proven the Fitz bottomed out on it and left some of her pieces between the wreck site and the shoal.

 

[JohnN]

If you look, you'll see a post made here on SB about some of our members who recently completed a dive beyond the 600' mark.

Edit - Link: http://www.scubaboard.com/forums/tek-trip-reports/422349-add-helium-dive-team-completes-dive-652-feet.html

Nice link, but I think you made my point. I count 9 support people (not counting the camera crew). Hardly a recreational dive

 

[Dave Sutton]

I don't mean to argue with you I just have strong feelings about what a shipwreck at the bottom of a lake/ocean means to the families of the crew who may have died.

Bob

Then you have strong feelings with diving nearly every wreck in the Great Lakes, the vast majority of which went down with total loss of life. The 1800's wrecks had a nearly complete history of 100% casualties. Many other later wrecks are the same. There's no difference between us diving the Carl D Bradley and diving on the Fitz.

It's certainly in the range of accessable wrecks, but would be a challenge thermally. Comparing it to the dives done in Grand Cayman is like comparing the Andrea Doria to the Speigal Grove.

The bottom terrain is caused by the actual wreck itself.

The scalloping of the straight lines on her hull gunwales is caused by variations in towfish depth casued by sea state, possibly made worse by not having the fish deep enough, or towing too slow to reduce cable layback (likely done because the umbilical is too short to tow at the correct depth/speed). Result? The fish depth varies, and the scalloped image is the result. Fix: Calmer Days, or tow faster using a longer umbilical so that the catenary of the umbilical soaks up the surges of vessel motion.

Not that we've ever done any of the above... ;-)

Deep water is a challenge to small boat sidescan. At 450 KHz you can see reliably about 200 meters to each side, and the altitude above bottom should be 10% of the range. That means that you should be flying the fish at about 60 feet above the bottom. That's not really possible using lightweight (hand deployable, IE: not armored stainless steel cable) umbilical, even at three knots. Bottom line is that to look that deep with hand deployed umbilical, you need to have the fish hanging essentially straight down from the boat, meaning that you need to tow at nearly zero speed, where wave action really can begin to dominate the image. The bottom line is that you can look (sort of) but you cannot search an area using a system set up like that. The alternative is to use a longer and heaviier armored umbilical (smaller diameter, negatively bouyant, but not hand-deployable), and that means a powered reel... not something that most people have access to. Jitka and I do have one, and we run a Klein 3000 with both 100 KHZ and 450 KHZ transducers running at the same time. At 100 KHZ`we can look 1000 meters on each side... that's 1 KM, and we only need to put the fish down 200 feet to search in 500 feet of water. With 200 meters of armored stainless steel coaxial cable we can run that at 8 knots. That cable length lets us soak up boat motion with cable catenary. We do have a powered reel to haul it all back aboard though. GOOD LUCK hand-deploying a fish at the end of 200 meters of armored cable. Deep-water Sidecan stuff is expensive: Powered reels alone start at $10K.... without umbilical.


Not bad shots to start with. Looks like probably a Marine Sonic unit at 450 KHZ?


We are giving a talk at the Shipwreck and Technology symposium in Muskegon in a few weeks, and will be discussing sidescan in detail. Come and visit.

http://shipwrecksandtechnology.org/...lutionized-shipwreck-hunting-and-exploration/


Dave


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[Jared0425]

Dave, you are right about the fish. I've done quite a bit of work with sidescan. I was referring to the actual terrain in the area was documented by GLHS and navy sonar. The image was taken by a Marine Sonics 450. I see that the image is not as good as it should be. That's why I prefer the Klein system. The sound does not seem to be relfecting right causing the variations in image. It shows both wave and thermocline interference. Notice how the deck looks collapsed when she is supposed to be somewhat intact, but the sound is only reflected by the topside steel hull girders. As for the team and unit equipment I am not sure. These photos have been around for a little bit of time according to Internet sources but forwarded to me. I've been trying to get ahold of GLHS over other side scan images of wrecks in the area (closest is the Aurania about 4 miles away in 460), but waiting for response. I know GLHS has a better Klein unit and has better images, but I don't think they will share them about the Fitzgerald due to obvious political reasons.

As for diving the Fitz, there were probably more than Mike Zee and Terrance who dove her, but kept their mouths shut. Pilothouse is around 490' so only the top divers could get to her. In my opinion the Fitz is no different than other freighters that went down.

 

[Barracuda2]

Is it true that one of the crew is actually outside of the wreck lying near the hull? or is that just some wreck legend I heard?

 

[Dave Sutton]

GLHS has an old Analog Klein on the boat. I looked it over when I was aboard in Whitefish Point in August. It's "OK", and since they got it for free it's "great". sadly their experienced operator passed away last year and now they do not have a "really" knowlagable operator. What's nicest about it is their oceanographic reel and cable, which is longer than mine. We did look at their 'Fitz images, and they were OK. With that said, our Klein 3000 absolutely blows it away. Not a bad guess when I thought that it looked like a MarineSonics 450 KHZ image eh? Not a bad unit, but nothing beats a digital Klein. We can run at either 100/450 or 450/900 depending on what transducers we mount on the fish. Dual frequencies can be used at the same time, for range and resolution both. You do get what you pay for when you start laying out six figures for hardware. At 900 KHZ I can resolve the spokes on a bicycle.. at 100 KHZ I can look out *really* far... running 450 and 100 at the same time? Magic.

To the latter: All of the deep wrecks have human remains close at hand. Men are trapped below, and sailors drown at the surface and sink near the wrecks. Tens of Thousands of lost sailors are still in the lakes. Some are visible, some are not. When we see their remains we are reminded that we are visiting a special place. Their presence reinforces the fact that we are aliens there... anyone diving these wrecks and coming into their presence is reminded of the losses suffered. Typo Tony still lays pinned in the coal that spilled out, trapping his legs. Whitey is in the engine room standing his last watch, a sailor lays next to the lifeboat on deck of another wreck. It's part and parcel of the lakes. Saying that the 'Fitz is different is just not the case. Respect is earned by seeing... to see we need to visit.

We have a half dozen divers in our group that could dive the 'Fitz on three days notice. Support teams of 6 plus camera crew? That's for the tropics. Teams of two or three, diving unsupported? That's the way to do it. Ten minutes on the wreck with a rebreather... about a three and a half hour dive run time. We've talked about applying for a permit and diving it, but... really.. why bother. Glory has no value, and there are so many other things to dive and so many other things to find.


We are going to be doing some original searching in the spring, and we are happy to bring folks along to participate in real-world sidescan sonar application courses, so let us know.


Capt. Dave

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