One doesn't hear of this very often, and then you report two in recent days. Yes, backing can be a problem in more ways than one.

1.) If you back way too fast, without an extremely firm grip on the steering, the force of the water pressure could grab the wheel from an unattentive hand at the helm and slam the rudder to a maximum limit. There is a snubber in the lazarette that is supposed to soften the strike at the limit, but a greater issue is the potential to bend the rudder post.

2.) As noted in your situation, backing (or even a forward grounding with a shoal keel, in some situations) places the rudder at risk.

A recent thread here about building up a too-short rudder discusses the resulting handling if the rudder is short. The thread is called 'Rudder Mod', here in the Technical Forum.

My first thought would be to avoid shortening the rudder. A shortened rudder would change the great sailing characteristics, I think. Some Southeast-area owners will comment soon...they sail in skinny water, so I wonder what there grounding experience has been. Disclaimer: Others will know a lot more than me. I have a fin keel, and usually the Pac NW has very deep water. Except in the sand bottom Columbia River, our grounding risks are usually rocks, and can land one physical injury and a $20,000 repair bill.

Does anyone know just how much shorter the rudder is than the wing keel? Maybe some of our northern members still have their boats on the hard and would measure the difference of rudder depth for us. This measurment can be critical when deciding whether to back into a slip near the shoreline or going in to the slip nose first.

Mike,

My rudder is only 2 inches shorter than my wing keel. When I have run aground (almost always slowly and knowing it could happen at any moment), there have been times that my rudder is also in contact with the bottom. Fortunately, almost all of our seabed is sand or mud, as you know, so there has been no damage.

I try to avoid backing into unknown depths because the rudder is vulnerable. One of my greatest concerns is running in shallowing water with any wave action. All it would take is to have the rudder come down hard when the boat pitched up and there was a bump on the seabed. I had a friend damage his Tartan 3500 rudder that way.

There is certainly a point where you just can't reduce the rudder depth anymore without making the boat hard to manage. The Europeans who sail in even thinner water often have often gone to dual rudders like you see on Kirie Elite boats and some others, which lets you go much smaller and shallower. The Mk 2 36's look to me like they have a bigger rudder than my mark 1, but I sure wouldn't want any less rudder than I have right now.

According to the rudder size vs hull number diagram in the C36 Owners Encyclopedia, the wing keel MK I C36 rudder should be 46 inches top to bottom. I measured mine and it was over 50 inches. This past winter I modified my rudder to the later elliptical configuration and it is just over 46 inches long. I had to cut about 3 1/2 inches off the original to get the correct overall length.