Christina Lake
On the BC 3 highway about 7 hours west of Calgary (45min past Castlegar)
Spent a lot of summers on this lake as my folks live on it. Lots of private campgrounds, one large provincial campground at Texas point, and three boat access only provincial campgrounds on the west shore.
Very deep (250'+) and extremely warm mountain lake. Water is very clear and other than near the public beach at the far south end no weeds at all. They don't get much better than this for all your summer water sports.
Some of the campgrounds have their own marinas and boat launches, and there are two public launches. One at Texas point, and one at the Christina lake marina that has fuel docks.
Pictures left to right
Texas point boat launch, Boat launch at the marina, Picture on the water (Dads Sea-Ray on left Brothers Bryant on right)