color me confused... (not sure what color that is, but i'm sure crola made it)
are you asking for tips? or offering tips?
you can actually catch the alligator gar with a lot of types of bait... obviously you do need to use the L-XL rod and reel tho.
i got mine with the same rod / reel, which i think everyone would, since you can't get the better gear until after you finish all the missions.
for bait i believe i used the float with a large long range bait (however it's worded)
and yes it was the hardest catch so far. probably only took me two minutes to reel in, but it got really close a couple times to breaking free, one way and then the other.
you can sometimes use the environment to help. if your fish towards a wall or edge of the water they can't run so far, they will seem to continue even after hitting the wall but they won't get too much further that i've seen. so it's a bit shorter time reeling them in.
the other gar you go after later i couldn't seem to get with a float, so i switched to a swimming lure: fish gripper (forget if it was green or pink) and got it almost instantly after casting and starting to reel the lure. --- i tried being serious once, in 1989.. didn't particularly care for it.. so don't expect it to happen again.
Only 6.3 ft? No offense, but that's a pretty small one. You want to know an expert tip?
Real HARD until your character jerks the rod backward, now stop reeling for a split second to let the tension gauge move back a little, now repeat this process until the fish gets tired. This method will let you catch most large fish with little trouble. You might also want to get the 3 star rod/reel to make your life a little easier too.
I've put 100+ hours into this game so let me know if you have any more questions.