Try the KSL.COM Classified adds there is a section for boat time shares. Most of them are on lake powell and they are alot better deal than the marinas. Also you can talk people down on the price. The marinas like antelope point are expensive but are nice boats I think there web sight is Foreverhouseboats.com There is two more marinas on that side of the lake but I dont know if they do rentals. Hope this helps. Bring a fishing pole the striper fishing is heating up this year and will only get better.
they pretty much have 2 companies, one with the old boats (better for fishing but less comfortable) and the other with the blue/white boats, way more comfortable but less fishing space. for leisure, go with the blue/white boats hand down, fishing, go with the older walk arounds.
Lake Powell is further, but worth the drive IMO, much better scenery and not anywhere near as HOT as Mead gets in the summer....the heat at MEAD is almost unbearable at times..even when you are in the water. You will use your AC 24 7 and burn through the gas fast. $$$$$$