disagree about a bolt on keel.

My bolt on lead keel can (and has) taken more abuse than a fiberglass skin can. A hammer and bondo is a much easier repair than grinding out and re-glassing.

The problem with keel failures has been twofold. 1) The builder went cheap on the bolt size, quantity or material. 2) The designers attempting to make keels that are too weak for the stresses involved.

My one inch monel keel bolts are as shiny as the day they were installed 26 years ago. Pricey - yes, but a lot cheaper than loosing the keel and probably the boat. When it comes to bolts that will be in place forever and exposed to sea water even stainless is inadequate.

BTW, back to the rudders breaking, the only suitable rudder stock material is solid Aquamet 22 prop shaft stainless or solid bronze. Hollow tubes are far weaker, and, of course cheaper for the boat builder.