In reply to Reefed One about the pole in the middle, there is a support beam running fore and aft in the middle of the boat. I don't know if it was to try to stabilize the frame or hold the tramp up.
In the Nacra 18 Square I had in the 80's, these fore and aft tubes were used to prevent rotation of the front and ream beams. Later, Nacra was able to eliminate the tubes (on the N5.2) by putting fittings inside the end of the beams that screwed into the hull and prevented rotation of the beam. I don't know about the Sol Cat, but this might have been the reason for the fore and aft tube, just like it was on early Nacras.
