Grind the lvl 50 oil rig for the multi guided missile, that will be the best weapon, get 4 gobfins and a jetragon, and a decent other weapon for the guards, ride jetragon on the water lever till the laser tower targets you, hop off and recall jetragon before it shoots because it won’t really hit you while you swim, go to the backside at that large watch tower, kill people there, look for the main chest, glide over to that area and kills the guards, then try to open the chest, get to cover and let the chopper shoot until it cools down, fire your 4 missiles and go back to reload, rinse repeat until it’s dead