The club requires 1/2" line. They do not specify type.
The mooring lines must be spliced with a thimble so that they can be connected to chain on the floating docks.
I mentioned 3-strand line because I am already capable of splicing 3-strand, including splicing the thimble into the line. On the other hand, I have never attempted to learn how to splice braided line. 3-strand out of convenience for mooring lines.
I am on Lake Ontario and the boat is presently in Lake Huron; It will be stored either with me on Lake Ontario or perhaps up in Georgian Bay... the jury is still out on that one. :-) At any rate, thanks for the heads-up on the course through West Marine.