Hi Nikos,
If you want to see what is coming before you hit it, you need to tow the ROV by the front. I don’t have a picture right now of the rope, but basically I attach it to both sides of the frame, just in front of the wing, and from there, to the tether app half a metre from the ROV.
You can see the size on this photo, I don’t have an exact drawing, If you need it I can measure it though.
The material is 6mm polycarbonate also known as plexiglass. IMO Acryllic sheet is to brittle.
I am sorry about the picture without buoyancy, you should certainly not remove it, I was doing some maintenance…
I attach the wing with 6mm SS screws directly in to threads cut in the frame. to keep the wing straight, you need a spacer under the wing in the rear screws app 6 mm.
Remember to cut holes for the thrusters.
Good luck 