I made this half wishbone boom from PVC pipe. The boom was filled with sand, heated with a heat gun, and formed. The mast gooseneck is a PVC "T" with a straight PVC insert. Both have a slit for the sail to exit on the side not seen here. The gooseneck is held in position by 1/8" braided line tied to its top and bottom, secured to the shroud ring above, and the mast base below. All joints are friction fit. No adhesive was used.The small jib is a commercial genoa from kayaksailor.com.
https://www.dropbox.com/s/88g8a1qg8y08b ... t.jpg?dl=0