This platform was made for a Hobie 21se. 4" pvc. Used full 10' lengths and cut the tee's, and X's in. Used street elbows out of the tee's in the corners. Top section was slanted about 15 degree's to allow the 21 to be pushed up onto the corregated plastic roofing sheets.
Worked well all summer. Glue failed when taking apart for winter. Risers did not need to be glued and were cut to make slant to water. $300 in parts