What does rolling do for Fish?

Solution 1:

The general consensus is that this skill is somewhat hard to use and learn, however if used correctly, it can be a significant help. The main uses for it are dodging bullets, and moving fast. The combination of these two uses allow for you reposition yourself into a useful location, such as into melee range while dodging bullets. You can also use your weapons while rolling.

Here is a nice discussion about whether or not it is useful.