If you know where it is, you can either Bubble Shield Run to it (as in, Forging in a Bubble Shield set to instant respawn at the perimeter, deploying it, then spawning another at the edge of it and deploying that, over to the Skull), or build a corridor using the Tube pieces to it.
It's also possible to fly over to it in Monitor mode if you can dodge the Guardians, but picking it up is going to be the problem.
It's also possible to fly over to it in Monitor mode if you can dodge the Guardians, but picking it up is going to be the problem.