When you finally gain unlimited access to the hoverboard there are two attacks to my knowledge that you can preform, one of which is also a speed boost. To perform these attacks, you must hit these buttons at the smae time: up+R1+X =flip attack left/right+R1+X =side spin move than when you hold those buttons when Jak lands, he'll grunt and you'll recieve a sudden speed boost. A sign that shows you've preformed the move correctly is that the hoverboard turns a bright blue for an instant then reutrns to its normal color. If you manage to hit a guard with these moves, it takes about 3-4 hits ti kill one. Note: the directional part of the moves must be done on the left analog stick.