My headsail was torn beyond repair in Hurricane Helene. It was only a 100% jib, which was very underpowered, especially in light wind. I'm getting a new jib via insurance, so are there any suggestions as to what size to get?
What is the best size headsail for beer can racing on Tampa Bay, for my Hunter 31 shoal draft boat?
- Thread starter plealman5
- Start date
I'm assuming you have the Hunter 31 which started production in 1983 and ended 1987. Sailboatdata.com shows a B&R rig with a backstay.
Normally I would say the 100 to 110 is the jib of choice for the B&R rig. But for this boat the main is smallish and looks more like an IOR main. SBD doesn't specify if the rig is fractional or masthead. I would think a 135% would deliver the performance desired without over powering the boat in 10 - 15 knots. At around 15 knots you would probably like a reef in the main to keep the boat on its feet.
On what basis do you think the 100 was very underpowered?
Normally I would say the 100 to 110 is the jib of choice for the B&R rig. But for this boat the main is smallish and looks more like an IOR main. SBD doesn't specify if the rig is fractional or masthead. I would think a 135% would deliver the performance desired without over powering the boat in 10 - 15 knots. At around 15 knots you would probably like a reef in the main to keep the boat on its feet.
On what basis do you think the 100 was very underpowered?
Shemandr,
My experiences sailing her in lighter breezes. It is a masthead rig. A 135% was where I was leaning. Still easy enough for my wife & I to tack, but enough sail for lighter winds.
My experiences sailing her in lighter breezes. It is a masthead rig. A 135% was where I was leaning. Still easy enough for my wife & I to tack, but enough sail for lighter winds.
I have an O’Day 322 which is a masthead rig. The boat came with a large 135 (maybe 140) Genoa. I confirmed with my local North Sail loft and we talked about how often I had to reef the 135…I sail on Lake Michigan near Chicago.
We decided to drop the size to about a 120. Like you, I wanted enough sail for light wind days, but did not want to reef every time the wind got above 15 knots.
I have sailed 2 seasons with the 120, and I like the size. I haven’t really missed much on light wind days, and I can use the full sail in a bit more windy conditions without being overpowered.
If you have a local loft, might be worth a call to discuss with them and get a recommendation.
Greg
We decided to drop the size to about a 120. Like you, I wanted enough sail for light wind days, but did not want to reef every time the wind got above 15 knots.
I have sailed 2 seasons with the 120, and I like the size. I haven’t really missed much on light wind days, and I can use the full sail in a bit more windy conditions without being overpowered.
If you have a local loft, might be worth a call to discuss with them and get a recommendation.
Greg
The masthead rig explains the need for a backstay and hence the smallish main.
I agree that a 150 is too hard to tack. It is more meant for a crewed boat who can be put on the rail to provide righting moment.
I always recommend consulting a local sail maker who knows local conditions as Greg illustrates .
I agree that a 150 is too hard to tack. It is more meant for a crewed boat who can be put on the rail to provide righting moment.
I always recommend consulting a local sail maker who knows local conditions as Greg illustrates .
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,327
By design, the Hunter sail plan was considered moderate to underpowered. Note that the boom length on the Hunter 31 (from the 80's) is 11ft long and later boats (Hunter 31-2 and the 310) use a 12.58 boom length. My conjecture is that the decision at introduction was experimentation with the B&R Rig and to assuage the marketing effort to get newer sailors into the cruising world and not frighten them by overpowering the boat.
Increasing the size of the foresail will affect the performance of the Main sail (the primary power source in the Hunter Sail plan). This can be problematic. Too much or too little sail in a given velocity of wind will induce lee or weather helm. To oppose the wind-induced helm, you must increase the rudder's pressure. This induces drag, defeating the reason you bought a bigger sail. Gentry, the 70's, produced some interesting work on the aerodynamics involved in the Main and Jib sails used to drive the sailboat. This one is on point with your concerns. ( http://gentrysailing.com/pdf-theory/Checking-Trim-on-the-Wind.pdf )
Regarding the opportunity to get a new sail and your goals to influence speed, I would spend money on the sail materials that have recently been developed. They will have the greatest impact. A cloth like North Sails 3Di molded composite, designed for your boat, would help optimize your boat speed. My first choice would be going to a loft and exploring their resources to get the optimum design. A foresail in the 115 to 120 range might be an optimum comprise. Once you raise that new Foresail, you're going to want to get the matching Mainsail.
I would also heed @shemandr 's advice, be ready to reef early. The law of diminishing returns comes into play as the wind speed increases.
Here is an interesting bit written about the Hunter 31.
In Hunter fashion, this model (HUNTER 31) was fitted with a B&R rig, which has a very racy look with its double swept-back spreaders. The mainsail carries a lot of roach, so even with a 135-percent masthead jib, the boat usually had a slight but pleasing amount of weather helm. Aquarius didn’t do well off the wind, partly due to the swept spreaders, which limited the extent to which the mainsail could be eased. The answer, which is the best one anyway, was to tack downwind. Aquarius wanted a reef early, in maybe 15 knots of wind; the large main has two reef points, both of which I frequently used. I found it fairly easy to balance the sails on a reach
Also check with your local PHRF handicapper to determine what the credits/penalties are for different size headsails. You don't want to order a new headsail that is on the borderline for a rating hit. I agree with jssailem that the Hunter 31 is underpowered with a sail area to displacement ratio of 16.17. A larger headsail will yield a narrower tacking angle and allow you to point slightly higher. If you're serious about racing, go big (140% min.) and reef when necessary.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,327
If this is a racing investment, I would spend a little on a spinnaker. I'd go with an asymmetrical and expect to tack downwind to maximize boat speed. The Hunter B&R rig has always punished the boat's direct downwind performance.
In racing, like in business, 'you are only as good as the power suit you wear to the meeting'. (Dress for Success)
In racing, like in business, 'you are only as good as the power suit you wear to the meeting'. (Dress for Success)
With that little main I'd go with an all purpose 135 and reef to keep the boat on it's feet.
Remember you're dragging the extra weight of that shoal draft keel around too.
My 2 cents.
Remember you're dragging the extra weight of that shoal draft keel around too.
My 2 cents.