Listen faggot. First of all Skygirls had a plot, you should read it sometime, it goes like this:
In the future, there were nanomachines, they were made for living forever, but ended up as war machines, they turned on their masters and as such, became very resistant to CONVENTIONAL WEAPONRY.
Now, in order to combat this threat they made the SONIC DIVER. This is a machine that relies on the innate abilities of the pilot to transfer data via the MOTIONSLIT which is the uniform they wear.
They always wear that uniform because it is the device they control the sonic diver with, ALSO they can be scrambled at any time, that is why they normally have them on around the base.
Now, the reason they can fly with their motionslits (NOT SWIMSUITS/UNDERWEAR) is because they apply a thin layer of NANOSKIN.
This acts like a barrier and protects them to upto 2 tons of external pressure. Therefore negating the need any form of cockpit armourment.