Here is a SI image example that clearly depicts the fact that the SI beam extends past vertical ...
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Rickie
So I made some testing, and it came out with even more questions than answers.
Pictures are quite self-explanatory. I idled repetitively along vertical pipe in various distances and directions. I got inconsistent and strange outcome. Sometimes the pipe can be seen on both sides (confirming SI overlap hypothesis) but sometimes it is not.
Also, the closer I went to the pipe, it shows less in the second SI beam. This should be the other way around. Could you please somehow bring some light to this?
I also made other experiment. Also, inconclusive. I run recording and on a stationary boat tied to a dock I tried lover underwater camera along transducer and I try to see if it will be visible on both sides. It wasn't. It wasn't visible at all until I move it quite far from the transducer to the side. I can see it perfectly on DI and 2D, but not on SI. Si start to pick it up when it was at lest 30 cm to the side from transducer, regardless of depth. It could be caused by interference in close range from transducer, or I was unable to place it on correct place in front aft plane. So I need to come with something else. I will most likely place some hollow sphere in water some 3 ft off bottom and I will try the same thing as I did with that pipe. I will do it in deep water >30ft to get decent SI overlap (if it exists) end I will idle around in various distances. This will hopefully solve this for good.
edit: one more thing. I have some shaded area in the left beam because of my trolling motor on the left side. So it could be, it is not past 90 beam cover (overlap). It could be simply reflection from motor casing. It is consistent with showing itself only when I pass it on starboard side.
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