As Tech Librarian I try to keep a watching brief on all technical topics and this problem of Marvin's continues to puzzle me. From the drawing in the Tech Manual the keel looks to be much the same as the arrangement I have in my 21 except that the blade only weighs 300lbs rather than 500lbs being made mostly of GRP and wood with a few steel bars and a bronze shoe.

The keel can't fall out through the bottom because the slider plates fore and aft can't get through the foil-shaped hole in the bottom of the hull.

If the "safety strop" is to prevent the plates reaching the bottom of their tracks, then is the blade loose in the box when fully down? Doesn't it wobble about and make a noise under way and at anchor?

Wouldn't it be better to let it go right down so that the slider plates take the weight and stop the wobble? That seems to work with my 21 which has the cast iron blade. The strop looks the same but is only really there to attach a bungey to as a depth indicator. It certainly wouldn't stop 500 lbs of iron falling down to the bottom of the track!

Geoff