Which head sail for maximum power.

Jun 18, 2006
59
hunter Cherubini Hunter 37 cutter Cocoa Beach
Given the choice between the two sails on the front or a37c, if you could only put one up in light air, which would it be? The easy answer is likely the jib but with the Yankee Cut I'm curious if it's really that efficient of a sail, per square foot. Thanks
 
Jan 7, 2011
5,828
Oday 322 East Chicago, IN
I don’t have a Hunter 37, but I think the answer really lies more in what sort of conditions you normally sail in.

I sail on the south end of Lake Michigan, and often have too much wind. Other days, I am blowing on the sail to try and get a breath of life into it.

My boat came with a 130 genoa, but when it was time to replace it, and after discussing with the sail lift, I decided to make it a 120. I was reefed so often (with the corresponding poor sail shape) cutting it down some made sense.

I sailed a lot this last season and was able to keep the sail fully deployed fairly often, and didn’t miss the extra sail area too often (Zi do have an Asymmetrical spinnaker to fly if I really feel like it).

My friends sail a Hunter 33 with a rather small, yankee cut jib. While they can see better than me with my deck-sweeper, I can often keep up with them or outsail them with my larger Genoa.

Greg
 
Jan 1, 2006
7,758
Slickcraft 26 Sailfish
At first this sounds like a trick question. The answer seems to be that the larger sail area of the jib would be better in light air. But Greg is correct - it depends.
If its very light air the presumably more full shape of the jib may have too much curve to keep airflow attached and the airflow that isn't attached is drag. Whereas the smaller Yankee may be able to be trimmed more flat for better attached airflow and less drag. I believe that the lion's share of drive in an upwind sail occurs in the forward third where the camber of the sail is. The aft 2/3 are supposed to be flat. Additionally, the Yankee would be more easily trimmed for puffs and sudden wind direction changes (Don't use the rudder).
On the other hand, the Yankee may constrict the slot depending on where it is sheeted. On a cutte, which is not an upwind rig, I'd expect the Yankee to sheet outboard. So not so much slot choking.
That's only going upwind, or close reach for a cutter. Downwind it is the barn door principle. Pole out the jib and go.
 

Johnb

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Jan 22, 2008
1,479
Hunter 37-cutter Richmond CA
Back in 2009 in a thread titled
“Changing yankee jib to 150 Genoa on H37”
this topic was discussed by some of the most knowledgeable HC37 sailors you will find.
 
May 31, 2007
779
Hunter 37 cutter Blind River
In light air, definitely both head sails. If only one allowed, the yankee. The yankee is far more efficient since it creates some slot. It is also bigger. When. I ordered new sails, I had the yankee made 3 ft. or so longer on the leach and foot. Vast light air improvement.