Never heard of this one.(boat technique)

[WaffleJaw]

I know in the past we talk about how fish hear...Low vs high frequencies,etc
Well I went fishing saturday morning with my buddy,and we talk about our friend's trip.....We have a friend that never fishes,but his dad does all the time...So of course,this friend goes out with his dad and a guide and catches 30+ strippers plus 6 catfish one weighing 17lbs (using the ribcage from the stripper)

and yea.........Im still a little pee'd about that!..Our friend ,who is a gaming nerd,just goes out and catches more fish than me and my buddy could ever do in one trip.
Anyway,lol
So of course we ask him how did they do it?....Well they started by finding the shad by watching the birds dive and using electronics...When they found that..They used swimbaits and just sunk em(Im assuming dropshots,but I forgot to ask)...When they werent biting the guide said ''well make em bite''....He took a rubber mallet and went to front of the boat,got down and started hitting the side of the hull...My buddy said within 15 seconds two poles went off and they landed the first two strippers

I still havent quite wrapped my head around this one?