Question: I have an old in mast furling system by Hood. What sailing improvements could I expect by converting to a traditional full batten main on a track? The boat is a Kelly Peterson 44 1977 vintage.

Answer: "Roachless / battenless "furl into the mast" mainsails may be easy to handle, but they have two disadvantages:

1) They must be cut quite flat in order to fit into the mast cavity without excessive bulk and / or wrinkling

2) They lack all the sail area that would be in the normal roach of a traditional mainsail.

These two factors result in a mainsail that is less powerful in terms of both sail area and camber, and as a result the boat will sail slower and point lower than it would with a larger, deeper main.

Just how much speed and pointing might be gained by going with a traditional larger and fuller main is impossible to predict, since many other factors such as hull form and ballast, headsail shape and overall sail trim have an influence on both speed and pointing. But it would not be unusual to gain from a half to a whole knot of average boat speed, and as much as 10 degrees of pointing ability."