The way I see it, shipwreck hunting definitely requires luck, knowledge and of course good GPS/sonar. Fish-finders are designed for finding fish only and they have low range action. Some combo units, like the one Ive seen (M25/M37) have a pretty good transducer with 4 even 6 beams which covers a good area all around the boat. It also provides an extremely wide area of coverage, starts with two 450 455 KHz beams uninterrupted side to side and covers 160 ft. which is not bad for a fish finder.
This would reveal fish and structure to the left and right of the boat as well as bottom composition in case the wreck rests in silt or sand. The best thing to my knowledge is the Side beam view which gives a more readable image of the bottom.
StingRob
This would reveal fish and structure to the left and right of the boat as well as bottom composition in case the wreck rests in silt or sand. The best thing to my knowledge is the Side beam view which gives a more readable image of the bottom.
StingRob