Last year we were fishing and some men came along and asked if we could find their sunken sailboat. We tried for a while with my Lowrance Elite 5 but ultimely failed. Friday fishing the same lake and just putting across the same area THERE IT WAS. The Helix 9 SI gen 1 with a hd transducer fount it. Deep too. The men were going to surface dive and attach a rope. It must have been too deep for them or they never found it.