It's common practice to have the diffuser head sitting in the water column like a dinner plate sitting on the table...parallel to the water surface.

It will be challenging to suspend the diffusers in the water column so that they are situated as such with just one buoy and the weighted line hanging off. It may be spitting hairs to say the the "have to be" that way, but I think they will lose some of there efficiency.

If you choose to build Princess Leia's head to split the difference, try to mount the line so that it hangs straight down from the center of the assembly and the buoy rope is mounted so that it comes off high in the center of the assembly. A weight,along with the line, hanging down might help stabilize it.

Sketch up your design and share with us for ideas before building.

Fish on!,
Noel