All three sharks are killed in almost the same way the first three sharks is killed in the 'Jaws' movies. Blown up with gas, electrocuted and the last one is blown up.

In both Jaws and Deep Blue Sea there is a scene involving a license plate. In Jaws it is removed from the belly of the dead tiger shark. In Deep Blue Sea it is removed from the teeth of a tiger shark.  Not only are both sharks the same but both plates are from Louisiana. The license plate number is the same in both films: 007 o 981 Exp 72-73.