If only?

The 4000 and 5000 have a very different hull shape to a 49er. Just look at one alongside a 49er and the differences are vast.

 IIRC, the Lasers have vastly more rocker along the chines and keel (slower at high speed, probably better in light all else being equal) more U-shaped sections rather than Vee (lower wetted surface area but probably inferior high-speed handling), more beam forward (better in light airs perhaps, not as fast upwind in chop but easier to handle especially throough the zone of death).

Phil Morrison has said that he designs his boats to be fast in light airs and easy to handle in strong winds. Julian doesn't worry all that much about light airs and even by skiff standards his boats are not at all that easy to sail in strong winds and chop. So the designers have very different ideals in things other than weight.

Originally posted by Phil eltringham hull will be about 65kg instead of nearly twice that, ask CST for a mast section and put a masthead kite on it and it should be able to give the 49er some reasonable competition.

Frankly I doubt it. The 49er hull is a far faster shape.

Originally posted by Phil eltringham I the class association now have the 5000 moulds, you could borrow them and build one in pre-preg carbon/kevlar sandwich, hull will be about 65kg

I remember hearing that the prototype 5000 hull was something like that.

You could do the change over in several stages first replace the hulls on existing boats then move onto developing the rig 

Sounds almost like a Boss - why did that not succeed. Can never understand why the 5000 was more popular than a Boss.

Just take the equalising weights out and you would be half way there