I just purchased a SIB, its deck extends past the transom to function like integrated trim tabs. This feature is great, except it causes nightmares with the idea of mounting a fish finder.
I did not find anything on here to point me in the right direction so I thought I would post my solution on here in case someone needs it in the future.
provides a transom clamp-able angle adjustable boom arm just for this purpose.
Sorry if this sounds like an advert, but they had what I needed.