Photo shows pretty clearly how my "cheapskate" ski boom is rigged. That's aircraft aluminum for the boom, EMT for the brace holding the wood triangle vertical. The skier pulls the boom down to her using that hanging line. She is pulled by the SINGLE line running forward from the boom end, through the bow lifting ring and back to the boom. That thin black line running aft from the boom is hooked to the vent on the aft deck. It keeps the boom in place when there is no "pulling load" on the boom. The white "lifting line" terminates in a jamb cleat, permitting vertical adjustment of the boom. A small line at the base of the triangle is tied to boat's grab rail keeping triangle from moving fore and aft. Two pieces of carpet prevents the deck from being marred.

A "real" boom sells new for $600. I figure I have about ten bucks in this one. And, it works: