SUGGESTION FOR MODDERS: Underwater Compartments 1x1 or 3x3

Currently, all underwater compartments for underwater bases, modded or vanilla, seem to be 2x2 in size. We cannot use them for a place that is 9x21 (below our tribal rafts on our WaterWorld server).

Can anyone create underwater compartment parts that are 1x1 in size, or (even better) 3x3? Look at the underwater compartments of the “Structures Plus” mod. These compartments function just by their own. But different sizes needed. That would help a lot. Thank you.