Problems with support structures

[Rbrks329]

I've been getting awful problems in the surface of my prints above where support structures are generated. Here's a picture:
https://1drv.ms/u/s!AsS5zgdczjMehkqzeje3Nvl-mppj
As you can see, while the surface of the hull is supposed to be smooth, it is riddled with infuriating imperfections.
I'm a complete novice to 3d printing so it's safe to say i have absolutely no idea what's going wrong. I currently use slic3r, but am learning to hate it due to how the supports structures are hard to remove after printing, on top of the problem I've just mentioned.

Any help is most welcome.