Sark keeps abusing the exploit that if you enter first person perspective mode that you can see through walls by walking up or swimming up to the wall, clipping through the outer layer of the wall (that you can see) and than seeing through the other sides layer cuz your looking at it from the back.

So basically you can't see the inside layer (opposite side of what your looking at) cuz its pointed the other direction, so you see through the wall cuz the graphic covering the opposite side only points the other way and not inwards.

Could solve this by simply adding the graphic panel from the outside to also point towards the inside so that if your looking at the inside of the wall or platform you would see the opposite side wall and thus not be able to see/clip through the wall since even if they clipped through the front layer they are facing, if you had the other side also have graphic inside of it, than you wouldn't be able to see through the 2nd layer that is the other side of the wall.