Boat Design and Pointing Ability

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Gary Wyngarden

We were out sailing with friends a couple of weeks ago, they on their J 24, we on our Hunter 335. We rafted overnight, grilled salmon off the stern rail and generally had a terrific time. A source of frustration for me was how much higher the J 24 can point compared to our 335. Even with the genoa all the way in and the traveler over so the boom is amidships, Shibumi can only make about 45 degrees off the wind. Push her harder and she begins to stall. The J 24 was able to point 5-10 degrees higher. This got me thinking about what aspects of boat design affect pointing ability. Hull and keel shape? Sail configuration and rigging? Any thoughts? Gary Wyngarden S/V Shibumi H335
 
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Dave

45 Degrees???

if you can only point 45 degrees and are allowing leeway, and drift from currents then my guess is you can not make any distance going upwind. My O'Day 35 can point about 30 degrees apparent. The Hunter 335 has a special rig and a large roach mainsail, with a fairly small jib in comparison, but it sounds to me like a sail trim problem. I'm sure the hunter should be able to point higher than that. Some offshore boats have the shrouds led to chainplates on the outside of the hull which limits your ability to trim the headsail but the hunter should not have that problem. How old and used is your mainsail?
 
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julian

pointers

sheeting angle on J24, being a racing boat is much closer to centreline. Racing (or more expensive) sails with a better cut will have a v big effect. I got a new tape drive genoa from UK sails this year for my 310 and difference is terrific.
 
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LaDonna Bubak - CatalinaOwners

Holy cow, what a question!

Hull shape, weight, rigging, sails, engine size, etc ALL have to do why a J24 points better than a Hunter. But I would guess that the interior is, shall we say, sparse? If you're really interested as to WHY all those components work together to make a faster boat, I'd go to the library & check out some design books. Or check out our "Chandlery" & pick some from there. I have no clue about how they all work together but I can tell a fast boat when I see one! :) LaDonna
 
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marv otto

Closer than 45 degrees?

Teach me somebody. I thought 45 degrees was as close as one could sail to the wind because of the physical principals involved. Have I been misled? What is the explanation for being able to sail 30 degrees?
 
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Dave

Apparent wind

The angle you can sail in relation to the wind has a lot to do with the boat design and sail design. How wide are the spreaders and shrouds for instance. is the mainsail strectched out or new. Also the wind direction the boat sees is different then the true wind direction. The boats speed thru the water creates relative wind in the direction of the boats motion. This is added to the true wind and creates what is known as apparent wind. This apparent wind angle will be closer to the bow than the true wind angle. The sail is designed with some twist to it because wind at the surface of the earth is effected by drag so the true wind direction is different at the top of the mast than at the surface of the water. There is no easy answer to your question but on my boat I always sail at 30 degrees to the wind angle as it appears on my wind angle instrument. Thus I tack thru 60 degrees apparent. Hope this helps. Keep in mind as the wind strength increases you will be able to point closer to the wind also as the effect of lift on the sails is greater.
 
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Miles

The J/24...

is a quick little racer, I'm not suprised they can out point you. But I am a little suprised that you can't get higher than 45 degrees without stalling. Dave might be onto something, perhaps you are talking about true vs. apparent wind angles? Our 340 can sail as high as 30 degrees apparent wind in decent conditions but speed drops off considerably the higher we point. Just falling off 5-10 degrees gives us another knot easily. They might be faster but your boat is a lot more comfortable, apples and oranges. I guess that's why some people end up being multiple boat owners, there's a scary thought ;.)
 
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Tim Schaaf

Apparent or true?

Are you 45 degrees off the aparent wind or the true wind. If you are refering to true wind, so that you tack through 90 degrees true, you are not doing that badly, although in flat water you might be able to tack through 80 if you pinch a bit. If the 45 degree refers to the apparent wind, then look more closely into what you are doing, as the previous posts have noted. YOu might consider asking a friend who races to come aboard for a sail. There are so many things that make a boat point higher and sail faster. The reward is great, because faster usually means you are sailing better, which is also safer, faster, and easier. Strange, but true, although all those people sailing on their ear in heavy winds without reefing, clearly do not believe it! Good luck.
 
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Ed Schenck

Which, 5 or 10?

From my limited experience it would seem like a big difference, 5 or 10. A J24 should easily outpoint the best Hunter by 5 degrees. But if it is 10 degrees then you have room for some improvement. Sails and sail trim have been discussed(see link below). What about tuning the rig? There are many discussions on the HOW site about proper mast bend and stay tension.
 
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Gary Wyngarden

Clarifications and Thanks

Let me clarify a couple of points I made. Shibumi's optimal pointing angle seems to be where the tail of the wind vane is aligned with one of the legs of the "vee" of the wind instrument on the top of the mast. I've always thought that those legs were at 45 degrees off the apparent wind, but in looking at them yesterday afternoon, they may be tighter than that. I'm thinking about sending the mate up in the bosun's chair with a protractor to check this out. ;-) In a good blow, we can do a little better than that. I'm not sure how much higher the J pointed, but I know he cleaned my clock on the upwind beats. But guess whose cockpit we had drinks in, and cooked and ate the salmon in. We can also stand below decks and he can't even sit up. Each has its advantages. Your suggestions are good ones. Our main is 9 years old and does have some wear. I think the mast rake is good, perhaps too much if anything as we have a pretty sensitive weather helm. When the genoa is hauled in to the shrouds I don't know what else to do. When the main is sheeted in as far as it will go and the traveller is to windward so that the boom is amidships, I'm running out of sail trim options. Thanks for your suggestions. Gary Wyngarden S/V Shibumi H335
 
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Bryan C.

Old mainsail

If your main is 9 years old and baggy, that will have a huge affect on pointing ability. I bent a new main on our boat last year replacing a 12 yo bag and the difference on all points of sail was immediately noticeable, but especially pointing. Now much closer and faster. This is with the original old 13 yo jib.
 
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Rob Rich

J-s are built for racing....

Everything about them is designed for efficiency and speed. I crewed on a J-24 for a few seasons, and they simply go like hell (though not as fast as my catamaran). But there's nothing like bringing 6 or seven people out and just having a blast going nowhere. I raced my C-27 recently. Mainsail is all blown out, and I couldn't keep up with anyone. It annoyed me for a minute, and then I remebered why I bought her. If I wanted to spend all day on point and whip ass, I'd have got a J or a Corsair. So I just giggled and looked forward to a good night's sleep, which is a pretty rare commodity on a J-24. Enjoy, Rob
 
Jan 22, 2003
744
Hunter 25_73-83 Burlington NJ
from the DESIGN point of view

As I noticed Mr Wyngarden did suggest there were DESIGN considerations here. May I make a few brief points about that? First off, a lot of people seem to imply that a boat's pointing ability depends on a number of things in combination. This is true. But certain attributes, which the J-24 possesses by design and the late-generation Hunters do not, will always indicate better performance upwind. In no particular order they are: Ballast to displacement ratio-- the more of the boat's weight in the keel, the tighter it will sail all round. 40% is nominal for racing boats. Concentration of available weight amidships-- it's not just like having a 50-50 weight distribution on a sports car, but in having as much of that moment as possible with the shortest arm as possible. Excess tendency of the boat to 'hobby-horse' due to weight masses at the ends will always adversely effect performance, especially when it's designed in and not bcause of stowed gear. Long leading edge on keel-- the 'bite' that helps a hull hold course. Most shoal-draught boats will never perform well for this alone. Hull shape-- fat, deep, round-section hulls never point well. The deadrise should be relatively flat and the underbody shallow (and the boat should be sailed as flat as possible). Proper rig design including imposed mast rake, as appropriate, to maintain centre of effort about 15% of DWL forward of the centre of lateral resistence-- meaning the boat carries a bit of weather helm by design, thus causing her to tend into the wind. Gear and crew weight distribution can do a lot of harm here but so can failure to tune the rig properly, or a poor rig in the first place. Sail area to weight ratio-- the horsepower-to-weight ratio of a car. Underpowered boats never point well. Many blase cruising boats have shockingly small (and short) mains. Aspect of rig-- tall narrow sails tend to do better than shorter,deeper sails. The optimum is probably a dinner-knife shape. If your main has the profile of Scarlett O'Hara's skirt you are not looking at a boat with alot of upwind performance. FLAT sails-- they are meant to be kept flat. This includes mainsail trim-- the sheet point has to keep the boom as level and as close to the wind as possible. FEW boats without travellers enabling the main sheet to be brought upwind of centre will point well. Condition of maintenance and gear weight I would say is a nominal consideration. A slightly overladen boat of a good design will outsail a tub stripped to the hull. Lastly, as Mr Wyngarden points out, his boat and the J-24 are apples and oranges. He has cocktail parties in his cockpit and the other people can barely sit up (under that infamous leaky deck-hull joint!) in their lightweight day racer. If you want cruising performance you are going to sacrifice sailing performance. In a 33-ft boat I doubt you'll ever have it great both ways. BTW- the Cherubini 44 had a ballast-to-weight of 40% and the long sloping forefoot acted like the leading edge of a fin keel to make it point with the tenacity of a razorblade in cheese. Under about 40-45 ft LOA you will only be looking at performance-vs-utility compromises. JC 2
 
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