Personally, fully knowing that BOAT stands for Break Out Another Thousand, not to mention the time you have invested in your skis.. I can fully understand why you don't want anyone else to ride, especially the hothead riders that love doing spins/360s/try to throw themselves off and basically abuse PWCs (or the newbies who run the engine right up to the anchor line or beach before shutting down)
That said.. I bring 2 skis with me anywhere I go as it's more fun (to me) to ride with at least one other buddy. At first I have them pay the launch fee on my 2nd ski, nice and cheap just to get them the bug, after that they pay for gas on one/chip in for oil (It's like selling drugs lol, hey man just try it, this one's free)
Granted, I work for an automotive company and most of the guys who go with us are gearheads.. If something breaks we fix it together.. I guess we're an odd bunch - we even swap cars at the track to see who's a better driver..