IMHO, the OP (an accomplished sailor) has been getting a lot of very solid advice in this interesting thread, but looks a bit fixated on the rudder ventilation issue.
I am in full agreement with Donalex that the effect of the major lateral shift in CE caused by excessive heeling can easily outweigh the effect of any forward shift due to sailing under jib alone.
This is further illustrated by the OP's own description of heeling and rounding up under a small jib. Since few coastal sailors routinely deploy separate staysails or stormjibs the usual solution to depend on a deeply furled genoa is unlikely to produce the desired degree of flatness and twist necessary to minimize heeling and maximize lift in high wind conditions.
This not to say, of course, that added rudder surface might not be beneficial as well. The suggestions provided by Shemandr, i.e. to add rudder length rather than width, look particularly appealing, especially if cost considerations do not allow the "cadillac option", namely dual, canted rudders.....
A fourth approach would be to add an accessory rudder, such as Scanmarine's Autohelm windvane rudder shown below. This was the configuration our Legend 43 "Rivendel II" carried for over a decade on her North and South Pacific wanderings. Although not primarily installed to increase rudder area, the effects on providing additional lift and directional stability were quite marked, e.g. when heaving to.
Fair winds,
Flying Dutchman
I am in full agreement with Donalex that the effect of the major lateral shift in CE caused by excessive heeling can easily outweigh the effect of any forward shift due to sailing under jib alone.
This is further illustrated by the OP's own description of heeling and rounding up under a small jib. Since few coastal sailors routinely deploy separate staysails or stormjibs the usual solution to depend on a deeply furled genoa is unlikely to produce the desired degree of flatness and twist necessary to minimize heeling and maximize lift in high wind conditions.
This not to say, of course, that added rudder surface might not be beneficial as well. The suggestions provided by Shemandr, i.e. to add rudder length rather than width, look particularly appealing, especially if cost considerations do not allow the "cadillac option", namely dual, canted rudders.....
A fourth approach would be to add an accessory rudder, such as Scanmarine's Autohelm windvane rudder shown below. This was the configuration our Legend 43 "Rivendel II" carried for over a decade on her North and South Pacific wanderings. Although not primarily installed to increase rudder area, the effects on providing additional lift and directional stability were quite marked, e.g. when heaving to.
Fair winds,
Flying Dutchman
