Neeto. Its literally been thirty years since I've been in a kayak. A local non-profit group rents out kayaks under the Clemente Bridge and I keep saying that I'm going to walk down and rent one. I need to just go do that.
As I recall the jumping place was across the lake from Bolton's Landing and to the left. I think one of the trees had a white ring painted on it as a marker. You climb up a path from the water, and stand on a rock, You see a tree down below you. You jump out over the tree and the water appears.