Furling Mast Mainsail???

[Peter Taylor]

My 2005 Mk11 has a furling mast, standard rig, 135 genoa and fin keel.
I find the mainsail of hardly any value unless the wind is aft of the beam.

While typical wind speed is around 15 knots here in Melboune we do get many days with 20 plus. I had a foam luff added to the headsail which allows me to reef it and still get a nice sail shape for upwind sailing. In a really strong breeze I just furl the main completely. The boat sails like a dream on the headsail.

However with main alone the boat will hardly sail at all. Is it something I am doing wrong?
I have fiddled with everything I can think of-are there any rules for outhaul tension or anything else- any suggestions would be most appreciated.

[MarkM]

I have the same setup. Same results, light air we might as well use the engine. The boat sails almost the same if we do or don't have the main set. You can play with the outhaul and the vang but the results are minimum. Guess its the trade off for a simpler system. Doyle was offering a swing batten system with somewhat of a roach. But checking with one of the guys at the boat show he didn't have much to say about it so it made me skeptical. Dont remember how much but you would have to replace the main, not something you can add to existing. Sorry Can't be more help.
Mark

[plaineolde]

I have the standard mast, eg. mainsail with slides in the track. The boat does not sail well with just the main, no matter what the wind strength. It provides plenty of drive with a headsail set, but not on its own.

When coming into anchor under sail, I often furl the genny and sail the last bit with just the main. There's a significant drop in speed. I think the boat just does not sail well with main alone. That's probably made worse with the furling sail, though I have no experience with them.

Just my 2 cents (possibly worth even less).

[deising]

I, too, have the std main configuration (with slides and a closed foot) and the few times I tried to sail with the main alone it was pitiful.

Call me lazy, but when we go out for 1-2 hour day or eveining sails, I usually just use the 135% Genoa and get what seems like 80% of the speed I would get with both sails.

[Nimue]

Its pretty simple math actually. My 135% genoa is about 415 sq ft, my (standard, full battened) main sail is about 258 sq. ft. Then subtract some more 'virtual area' from the main where the luff has disturbed flow from the mast, lets say at least 60 sq. ft. It's not hard to imagine that the genoa is providing 2-4 times more power than the main when one sail is used by itself.

Certainly if you are sailing upwind using both sails will be much quicker, as the mainsail will allow you to load the foils properly, point higher, and have a little more horspower as well. But the genoa on our boats is the driving sail.