As a designer/manufacturer I think in principal that this is an interesting idea. In practice though it may not be as straightforward as the idea seems. There are presumably two interfaces to consider, the keel/hull and the hull/mast. Possibly the bulb/keel too but I think that keels and bulbs belong together, to seperate them could affect certain design ideas.
Looking at the keel/hull interface I think it would not be too difficult to come up with a ‘standard slot’. Pulling a number from the air 4mm x 32mm. Thinner foils could be built up perhaps and faired as usual, length is not an issue. Of course then it looks like we are setting a maximum foil thickness. I could not be in favour of a keel box agreement because they add excess weight. So we have to adjust different keels to fit… rather like we do now.
Mast/hull… here are a few base numbers, ones I am currently using. Kittiwake mast tube 9/32"OD,1/4" clearance ID. This works with a 1/4"ID aluminium lower mast, also fits a 1/4" dowel mast nicely as on the Pintail 12. A new rig I am working on will have a 5mm carbon mast, I intend to supply conversion collars where people want to use the 5mm mast in the 9/32" socket. Rigs on my boats will be designed to be backwards compatible (not always forwards). I am using a mast box on the new design to allow linear and tilting movement of the mast, the box will be a snug fit on the 5mm mast.
A standard socket/box width would have to be on the large side yes? With insert/liners to give compatibility. With the unavoidable mix of metric and imperial that could be a difficult task.
I don’t mean this to sound negative, I do like the idea in principal but the practicalities may make it difficult.
The old git… Graham