Author Topic: Help Identify Object (Read 34530 times)

HarrisonDawgs · « **on:** September 06, 2011, 12:16:36 AM »

New to this and would like opinions on what this is. Thought I knew for sure on first scan but other scans have made me wonder if I'm seeing what I think I'm seeing. Also I'd like some help from you veterans on appx length and width. Scans were taken between 3.4 and 4.8 mph (gps). Not sure of chart speed (it's new to me). I need to know how to tweak the machine for better pics but I'll read forums for that.
Thanks.

Roddy · « **Reply #1 on:** September 06, 2011, 02:34:05 AM »

Looks like a 4' X 14' boat in 26 ' of water. Nice screen shot.

Somebody lost a jon-boat . A good boat speed is between 2 and 4 mph with matching chart speed. Enjoy Roddy

HarrisonDawgs · « **Reply #2 on:** September 06, 2011, 07:43:43 AM »

Thanks Roddy. I agree. Meant to post a couple more pictures but they didnt upload. I'll get the hang of this eventually.

HarrisonDawgs · « **Reply #3 on:** September 06, 2011, 07:49:40 AM »

Here's another look....

HarrisonDawgs · « **Reply #4 on:** September 06, 2011, 07:54:24 AM »

Another...

HarrisonDawgs · « **Reply #5 on:** September 06, 2011, 07:57:54 AM »

One last pic

RGecy · « **Reply #6 on:** September 06, 2011, 08:45:07 AM »

HarrisonDawgs,

Welcome to the forum. I would agree. Probably could be recovered pretty easy. The scans look great. Like I tell most newbies, make some recordings of objects like this, and come home an play them back so you can tweak the settings to get the best image. The Humminbird units record the raw processed data and this allows you to change the settings on playback. Everything from sensitivity, Sharp, contrast, colors, range, chart speed, fish id, etc. can all be changed on playback.

Good luck,

Robert

sonar2000 · « **Reply #7 on:** September 06, 2011, 11:09:12 AM »

You might also try scanning with just the left or right transducer. That way you can cut the range down and maybe get a clearer picture...
Chuck

HarrisonDawgs · « **Reply #8 on:** September 06, 2011, 03:38:12 PM »

Thanks for all the help guys. I try what you all mentioned. New at this and dont mind being a newbie. Thanks to all you folks for getting me up to speed! Can't wait to try the recording.

HarrisonDawgs · « **Reply #9 on:** September 06, 2011, 11:18:13 PM »

Ok, confused a bit. Made a recording today and used hum view (which I am extremely new to) and found myself second guessing. The original shots and every overpass I have made look to be a boat, possibly a jon boat, rowboat or maybe even a small sailboat. New views leave me totally confused as to what this is. I have come to 3 possiblities 1) some sort of boat 2) manmade fish structure resembling a boat or 3) possibly a rooftop off of a boathouse that was removed (remodeling) and floated off and sank. Wondering what you guys think after looking at all the pictures. Will try another scan tomorrow.
Thanks

HarrisonDawgs · « **Reply #10 on:** September 06, 2011, 11:20:20 PM »

Need to click on last 2 images to see the full picture. Sorry guys, I'm learning....

RGecy · « **Reply #11 on:** September 07, 2011, 02:42:49 AM »

Still lo0ks like a boat to me. The only way to say for sure is to dive on it!

Robert

HarrisonDawgs · « **Reply #12 on:** September 07, 2011, 07:33:26 AM »

Yep, I agree. And I'm certified but havent dove in years. Might just try it but visibility is 18 to 20 inches at the surface and it seems risky for a surface dive. Not keen on tangling with something I cant see, even at 26 feet. Might just try a hook and retrieve. Then again I might just leave it there to practice scanning and maybe even catch a fish or two. Gonna make more runs and scans. Will post more picures if I get some good ones.
Thanks!

RGecy · « **Reply #13 on:** September 07, 2011, 09:06:26 AM »

I am sure there are some local divers who would dive on it for you just for the hell of it! If I was closer I would do it. It is certainly good for a little training mission for SAR divers.

Good Luck,

Robert

sonar2000 · « **Reply #14 on:** September 07, 2011, 09:31:00 AM »

If you are having problems finding qualified divers (those who are above recreational certification) you might look for someone with a drop camera or an ROV.
Drop cameras are more plentiful and the user usually does not charge for helping...
Chuck

Roddy · « **Reply #15 on:** September 07, 2011, 10:38:13 AM »

Looks like a boat to me. Drop cam job. I have a wk that is on the way between the boat landing and the sea that I use for test and calibration on each outing. Roddy

HarrisonDawgs · « **Reply #16 on:** September 07, 2011, 11:23:55 AM »

More scans but still perplexed. Some images look like 2 jon boats side by side touching lengthwise. Wondering if this could be some kind of echo. Wish I were more experienced. Made a very slow (0.1 mph) drift pass over it this am and this photo was neat looking to me so I'm sharing.

RGecy · « **Reply #17 on:** September 07, 2011, 04:09:07 PM »

You are just seeing where the SI beam overlaps a little. Here is a screenshot of a boat I found up near Georgetown SC that sank and killed several children. DNR had been looking for it for a month and could never locate it. I found it in the first 30 minutes using the Humminbird.

http://forums.sideimagingsoft.com/index.php?topic=108.msg213#msg213

Its only 26' deep. I am sure there are some rec divers who would check it out for you. Drop camera may be difficult if the vis is real low.

Robert

sonar2000 · « **Reply #18 on:** September 07, 2011, 04:46:58 PM »

I would be concerned about rec divers and that low of visibility. Best to find a qualified diver.
Lets be safe on this one.
Drop camera can show a lot in low viz, especially with lights and filters..
Chuck

HarrisonDawgs · « **Reply #19 on:** September 07, 2011, 09:33:57 PM »

Thanks Robert. I know what you are talking about by seeing images on both sides but that is not what I was talking about. Need to upload a picture of what I am talking about but on some of the side images (40 feet or more out) I see a ghost boat right next to the "real" boat. On the first couple of images I could imagine a thick rope tied to the bow that in effect wrapped around to the side just off the bottom about 4 feet from side of boat. The more I thought about it I realized this would be practically impossible for a rope to lay that straight down the side. Today I made some more runs and duh, it hit me. The sonar is hitting the opposite inside of the boat, reflecting to the inner near side of the boat, back to the opposite side and then back to transducer. That would explain the weaker ghost image of a second boat side by side. Don't know why it took me this long to realize except that I am simply new to side imaging. Actually what made me realize this is a scan along a bank where there was a tall grassbed about 5 feet off the bank. You could visibly see about 4 feet of cleared shallow water between the grass and the bank. Side scan showed 2 distinct parallel grassbeds where there were only one. I realized that some signal was reflecting off of hard bank, back to grass, and then back to bank again to cause this. (This type of grass has thick tall stems up to surface of water). It was at this point I realized why I was seeing 2 boats on the same side of the boat. Because of those pictures I was beginning to think it might be an inverted boathouse rooftop but now I realize my error. I'll try and find a pic that shows what I am talking about.
Again, thanks for all the advice and patience. Sorry this is so long. This is FUN stuff!

HarrisonDawgs · « **Reply #20 on:** September 07, 2011, 09:45:54 PM »

The following image should explain. Also wondering...if the "echo" is this strong would that possibly suggest aluminum (or metal) boat? Seems to me a fiberglass with proper insulating foam/upholstery would tend to absorb most of the echo...at least enough that it wouldnt appear so distinct.
BTW, great images. Thanks for posting.

HarrisonDawgs · « **Reply #21 on:** September 07, 2011, 09:55:10 PM »

This picture is one of the ones where I thought I saw a rope off the bow. I also wonder if it is possible to have right side sonar reflect off hard bottom ledge back across the water to the left side and then back to boat. If so, what would this do to image?? Same frequency on both sides of transducer, right?

Roddy · « **Reply #22 on:** September 07, 2011, 10:43:01 PM »

Hay is that a rod&reel in pix #7 straboard aft side? Roddy

HarrisonDawgs · « **Reply #23 on:** September 07, 2011, 10:54:32 PM »

LOL, I wondered the same thing Roddy! Looks suspicious huh? That picture was a superslomo scan - drift scanning...

Roddy · « **Reply #24 on:** September 08, 2011, 12:09:57 AM »

Slow is good!!

Roddy

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