I found the SC17 to be a lousy beginners boat. Nothing for the crew to hold on to on deck. sharply rounded decks very uncomfortable to sit on. The only time i had a crew get hurt badly was on one in a lake. the boat dived the bows under sharply and quickly and came to a sudden halt when the massively draggy main beam hit the water. With nothing to hold on to the crew injured her knee after being flung forward.
My friends wife also hurt her back when they tipped over. nothing for her to hold on to.
I theorize that the forward canting rudders have something to do with the bows of the supercats wanting to dive all the time.
Also the 17 was meant to be a 2 up boat when first sold. that's why they made a 15 for 1 person. There are boardless boats from many builders that can be sailed by 1 that were originally designed for 2.
My memory of the symetrical boardless cat evolution of the 70s-80s is as follows.(not including the kind with fins-dart type)
Sizzler-aluminum hulls
G-cats
Supercats
Trac 16
The Trac 16 was an improvement over the Supercat IMHO.
There was nothing faster than a G5.7 off the wind in the days before the assy. We worked our way up to top 3 once at Texel on the downwind after a mediocre start.