How about having it so once we get vehicles into the game, we can latch onto them with the grappling hook to hitch a ride? Pretty much the way it works in Just Cause 2. It'd be an epic way to make an escape, shooting your hook into your friend's getaway hovercraft and being hoisted away from trouble. (sure you cooould be boring and just warp back to your ship, but where's the fun in that?) It'd also be quite a nice tool for you pirates out there: perhaps ambush a passing vehicle or board an enemy ship. In a way it'd balance game-play by making vehicles a bit more vulnerable to those on foot. ....seriously though I just wanna be like Batman with the Sky Hook and make my epic get-away