what do you kill that monster with...a bazooka?
I hunted in Florida and we could not use firearms, except for a bangstick for the final kill.
I did it with a crossbow with heavy metal bolts and 600 lb test line attached to a buoy. Shot the bolt into the gator and then let him drag the buoy around for a while. After a bit I'd grab the buoy and let him drag the boat around until he got tired. Usually tried to stick him with a harpoon or something so he had 2 attachments, in case one came off.
When he got tired we'd pull him up and hit him with the bang stick right behind the head where the spinal cord attaches. The bangstick I used had a 357 round, that would not penetrate the skull on a bigger one, you had to get them through the spinal cord. That would usually stun them allowing you to grab the mouth and pull it onto the boat's gunnel.
Then we'd tape the mouth and using a knife make sure the spinal cord was detached from the skull. Then let him bleed for a while in the water and finally pull him into the boat. With a big one none of this was easy... The biggest I ever took was in the 10 ft range, the one in the picture was probably 12 ft or a little more.
Could take a few hours. And all was done at night in the dark, and the best hunting was with no moon, very dark. Even with the crossbow the range was limited, could not shoot with accuracy more than about 25 ft, and not at all beyond 50.
Gators are reptiles so even with the spinal cord cut and blead they are kind of still alive. They can thrash and kick for hours. Bite too, that's why the mouth has to be taped shut. I suspect the heart beats a long time.