Side scan pictures--what do you see?

[Nemrod]

What do you see with your sonar unit? Please post picures if you like and describe your successes.

I have had the opportunity now to get the Whaler out with the Humminbird 987c several times. I am slowly getting the set up dialed in. Here are a few scans now that I updated mine to utilize the "picture" capability with a SD card installed.

This first scan is of a freshwater wreck in about 90 feet of water, it is a paddle wheeler approx 60 to 90 feet long and three decks including the hull. It is an actual wreck and lies on a steeply sloping bed with some rocks and trees about. Last year using my Lowrance I was not able to positively identify this wreck because of the steeply sloping bottom and other stuff about I could not "see" the wreck positively. I know we saw it on the screen but I could not differentiate it from large rocks or ridges in the area. Enter the 987c, well, here is the difference and the picture speaks volumes:

Here is a picture of a narrow bluff that extends out into the water:

Here is a picture of small 30ish foot cabin cruiser. It also lies on a steeply sloping bottom with large rocks and sunken trees about. It is also sitting down in a ravine. I could not see this wreck at all on the Lowrance. Here you see it as a fuzzy spot sitting at the top of the ravine which also imaged:

My intention is not to say you need this sonar or to say that the Lowrance or similar units cannot be used effectively--only to show how useful the side scan feature really is.

If any of you guys have bottom freeze pictures over known wrecks and reef regardless of sonar type/brand, please post them in this thread. I think it would be instructive and useful for us to learn how to interpret the images we see and understand how things look with more conventional sonar/fish finders. In any case, I thought the above side scan images were fun and typical.


The console area of our little Whaler:

N

 

[Tamas]

Here is a picture of small 30ish foot cabin cruiser. It also lies on a steeply sloping bottom with large rocks and sunken trees about. It is also sitting down in a ravine. I could not see this wreck at all on the Lowrance. Here you see it as a fuzzy spot sitting at the top of the ravine which also imaged:

I don't see it, can you point it out?

 

[Nemrod]

LOL, yes, it is fuzzy because it is down in the ravine. Look up that funny looking diagonal line to the "blob". You will also see a tree above it and below it. This is not a clear picture like the paddle wheeler. The day before I got a better scan but did not hit the mark button. You could see the profile view. This is not an exact science and some things show better than others--even day to day. This wreck did not ever show on standard unit nor could I see anything using the 987 in conventional mode. The blob is the cabin cruiser. I circled back over and using GPS coordinates had my wife drop anchor. I found the anchor lying in the stern deck of the cruiser. The ravine that the cruiser lies in makes it diffucult to "see" the cruiser. Hope this helps. Like I said, this is not a science, it is an art. Something I am noticing, wooden objects and fiberglass don't show up as clearly on sonar as do metal and rock. N

 

[Tamas]

LOL, yes, it is fuzzy because it is down in the ravine. Look up that funny looking diagonal line to the "blob". You will also see a tree above it and below it. This is not a clear picture like the paddle wheeler. The day before I got a better scan but did not hit the mark button. You could see the profile view. This is not an exact science and some things show better than others--even day to day. This wreck did not ever show on standard unit nor could I see anything using the 987 in conventional mode. The blob is the cabin cruiser. I circled back over and using GPS coordinates had my wife drop anchor. I found the anchor lying in the stern deck of the cruiser. The ravine that the cruiser lies in makes it diffucult to "see" the cruiser. Hope this helps. Like I said, this is not a science, it is an art. N

Still cannot.....perhaps I am not looking in the right place.....care to circle it or point to it with an arrow so those that are not side-scan certified can also see it?

Or I am just blind?! Or blond? I dunno????

 

[Nemrod]

On my computer screen, see the boat arrow at the top of the picture and then look down approx one inch to the four or eight o'clock position and you see the "fuzzy blob". That is the cabin cruiser. It is actually sitting bow up slope and the bow is hidden by the ravine. What you are seeing is the stern and small bridge/helm poking out of the ravine. It does not look like a boat----you have to interpret it to realize it is not a natural object. Sorry it is not more clear--I was trying to illustrate both a good image and a poor but still useable image as would occur in typical conditions. The side scan beams look outward from the boat. The top of the screen is where my boat is and the image is updated as the boat moves along. The depths given in the upper left hand corner are not the depth at the imaged points but the depth directly below the boat. For example, the depth below the boat in the pic in question was 52 feet and I was scanning upslope to the cruiser hitting it obliquely in the stern down in the ravine at approx 35 feet deep. Your actully only seeing the stern and steering station, the bow and forward deck are hidden in the ravine.

Duh--I know--I used to be blonde.

N

 

[DennisS]

That is incredible technology in such a small package. I use a Klein 3000 when I work on an oceanogrphic ship. We map dump sites from harbor dredging, not very exciting. I'm impressed at the quality of the images from the Hummingbird. How wide of a swath does it cover.

 

[fire_diver]

I'm a little confused on the images. Why are the left and right screens mirrors of each other? Wouldn't they look different, like in the pics on the 987 website?

Second, where is that paddlewheeler at? That's not in TR is it?

Fiberglass is pretty transparent to RF energy, I imagine it would be hard to find with a sonar.

FD

 

[Nemrod]

The images do not normally mirror like that most of the time. I believe that sometimes it is ghost images from reflections possibly off the lower unit when the engine is trimmed full forward. I need to play around some more and figure that out completely.

Yep, that is in Table Rock.

N

 

[moneysavr]

The echo or as you call it mirror is because you need to go into advance settings and set your power to the depth your looking at if you like I can post a how to on set up on sonar units to help forward and bottom looking units.
I have the same type unit but 957 for the power to look down at deep wrecks and it can be hard but I did find a wreck several years back with a cheap locater and it was easy as a mostly flat bottom and then you have a 2-d spike and then flat bottom not saying it could of been a mass of other things but low and behold it was a cool shipwreck .
That said the technology is OK but it be nice if you had a fish in the water and could get done 50'-100' of water, and this unit its depth limited- this is a link to a story with the same type of unit that was enhanced or tweaked thru a computer program see link-
http://www.ufodigest.com/news/0906/kinrossobject.html
I feel with most forward looking and side scan units you are limited to going over known wrecks then need to interpret-side scan units are slow as related to the tow speeds that the fish will let you pull and man they are slow as faster you tow the fish lifts off the bottom even with depressors installed as with bottom looking sonar I can mow the lawn with limited coverage= but more cone angle at greater depths but with much faster speeds on good weather days i.e. no rollers.
I am sure once you get into your adv settings,turn the filters to low,get out on a flat day and go over a wreck in 50'fsw you can get a picture almost as they advertise in the sale brochure!
Dive safe,
Brad

 

[Nemrod]

Yes, I will take any links to info on setting up any type of consumer sonars and using them.

As to depth limitations, this 987 works down to 150 feet. It is not suitable for professional treasure hunters. The practical limit is about 100 feet. That paddlewheeler sits with the stern at about 80 feet and the bow at 110 feet and so therefore the scan I provided is typical of a freshwater scan in 100 foot depth. The depth indicated on the screen was the depth below the boat--not at the wreck. Saltwater is a more diffucult medium but my results indicate useability down to near the limits of sport diving. When I made this scan I passed almost directly over the wreck going from shallow to deep on a slight diagonal--and--slightly off to one side.

I suspect at greater depth there maybe some overlaps of right and left returns plus ghosting artifacts from reflections off the huge lower unit just a little more than a foot away.

Fish do show up on the unit as do bait fish schools. N