I am pretty sure the Singer Island waypoint will be just to the south of the Crown Plaza. There are a couple of swimming areas marked by buoys in front of the public beaches that the sailors have to watch out for. They should not be sailing that close to shore anyway. There is a slight chance the waypoint might be moved but the one I took was:
Latitude: N26°47.253' Longitude: W80°01.945'

I went to guestimate the coordinates for the start because I have the waypoint for Bostons and I saw a POI just to south of Bostons and low and behold it was marked Delray Beach Yacht Club. The coordinates near the ocean are:
Latitude: N26°27.427' Longitude: W80°03.517'

My roomate should be bartending at the Crowne Plaza then. Makes a mean Absolute Cranberry.

Hope to see y'all!!!