The ducers sit just fine I think. The structure scan one could be angled a bit further down though. I go out diving tomorrow, will post a picture of my ducer setup.
I dont think there is anything wrong. What kind of wreck is it?
Pretty deep scan. To low contrast, I would crank it up to 85%. I also looks as if the water is not calm. The bottom structure bounge quite a lot. That doesnt improve the result. Try to get it on the side scan also. It seems quite big that wreck.
A small wreck, probably wooden, gone into the sea bed. Also a bit deep for the 800khz. Tune up the contrast here also or switch to 455Khz. You will not get anything on the the side scan of such a small wreck when you go diretcly over it. Thats why you have it on the down scan only.
And remove those depth lines!
1. Down scan, german steam trawler WW1. 40m long
2. Side image, same as 1.
3. Side image, 65m long steamer, sank in 1886 (bubbles from the diver at the stern)
4. Down scan, 68m long steamer, sank in 1896 ( a bit to much contrast). From right you see the anchor on the bow, the front mast 5m high and the davids at the bridge section.