See if you can borrow Vans' "PowerGrinderII", this is a similar unit that Tony Soprano's guys use. Will gind up anything quick.
As far as extending, I would add sand, and get some bait fish from the dock....herring a couple of flats of bunker, add bunker oil and milt, and if they allow blood, visit a slauter house and get a 50 gal drum, run a hose overboard..a nice steady stream will go a loong way. Blood mixed with sand is great for bringing them to the boat but is considered unsportsmanlike
monster shark in OB?