An older friend of mine has started a debate with me about the physics of masts.

He thinks that if you had a mast that was perfectly stiff the boat would be faster than a boat with a semi flexible mast.

I started to debate back but I had nothing, all I could tihnk of was the ability to spill aire in big wind and not over power the boat.

Is there any other advantage to a flexible mast over a very stiff one?