Hey Tom,
The times I've capsized have been b/c of too much wind. I didn't like the stock sail design so I built my rig to use a standard Laser sail. Maybe you could call it a Turbo'd Spindrift! Was fine in the PNW, but once we got to San Francisco bay things changed. The first time out in Sausalito I was moving along and got a big puff of 20k+ and the boat just popped up on the step and took off, until seconds later when the rudder snapped. The next plywood rudder I made didn't last long in SF either. I finally got smart and built a rudder out of solid clear grain mahogany. We've never had a hard grounding under sail but I'm sure it would rip the rudder right off. We're still using the same set of oars. They're nine-footers (one piece) and pull the boat along nicely. Occasionally use a tiny 2hp pull & go, which will plane the boat if only one person is in it.