The anchor is a good idea. I sail on a lake too, on a longboard, and my preferred lauch point is bordered by pointy rocks.
When it's windy, it's is difficult to carry both sail and board since you have to take a few steps on the slippery and unstable rocks. Loosing balance could mean a hole in your sail or board! So I usually bring the sail in the water first, then run to shore and back with board before the sail is pushed on shore.
I will use the anchor to bring my board to water first, and come back without rush with my sail. It will also be usefull with the kids. They are unable to carry the stuff over the rocks, so they usually do the human anchor waiting for me. Trouble is, they will sometimes just leave their equipment there and get out quickly because they feel cold. I'm then stuck with two kits in the water!
Thanks for the idea!