Beating to Weather

[Bill Roosa]

OK, I guess you I get a case of beer

Apparent wind = true wind + boat speed assuming you keep all arrows pointing correctly in the vector diagram. And yes Martha the apparent wind comes forward as the boat speed goes up... but in a high true wind the apparent wind does not come forward nearly as much. And that was the thread topic. In a true wind speed that is close to the boat speed I don't do much better than 90 degrees tack angle so I apologize if I gave you the impression that I can always do that. I was only talking about pointing into higher winds and (presumably) a rough sea. The way I know I have 5 degrees leeway on each tack is by using the compass and GPS together. I have checked this numerous times. Lest I belabor the point(ing) ;-) you have to be able to get your jib clew inboard AND be able to shape the sail. Most standard setups can't do that.I suggest that the next time you go out and the waves are not flat and you are close hauled you get someone to stand next to the jib clew and have them pull it inboard and see for yourself what happens. Don't forget to readjust the sheets and traveler.For me it is all about entry angles and draft positions. For heavy seas more draft forward to get the driving force part of the "lift" vector pointing forward and then trim the tale tails to get the entry angle right.For lighter winds you have to deal with the wind coming forward more and to get enough power move the draft further back.Learn to read the tale tails. The fancy wind angle gage on the dash is fine for poking about on a broad reach and such but if you want to point the tale tails are the cats meow for fine tuning the sails.1. Tack2. Bear off to pick up the speed you just lost3. Start bearing up till the center jib tale tail inboard stops streaming4. Reel in the barber hauler till the tale tail streams again 5. bear up and re trimRepeat 4-5 till happy and watch the wind/waves and anticipate

 

[Ross]

Nancy and I spent a lovely day a couple of years

ago sailing up the Susquehanna River when there was a bit of current running and the true wind was straight down the river at about 6-8 kts. Our tacks took us east and west, the river runs south as did the wind. My sail trim was as though I was close hauled because the true wind and the current were south and my apparent wind was just enough north of east-west that we sailed for about three hours and worked our way about one mile up river.

 

[Rich G]

Motor-Sailing Concern

Generally, I use the motor to get in/out of the marina, when there's a deadline to meet and the wind isn't cooperating or if someone onboard whines excessively about heel. I know that having some sail up while motoring will steady the ride (albeit with more heel). I've heard that heeling while motoring may result in engine damage due to inadequate oil coverage to the windward side of the engine. Is this true? If so, is there a rule of thumb in terms of degree of heel up to which an engine won't be damaged?

 

[henkmeuzelaar]

No reason to heel much, Rich G

Just imagine being close-hauled and perhaps heeling quite a bit. Now just steer a bit further into the wind ("pinching") till your boat rights itself. Everything is fine now, except you're not making much speed anymore, right? So now you need to start your engine to keep your speed up. That's basically what "motorsailing" is all about! Since you are pointing higher (sailing closer to the wind) than you would be able to do without the engine, this is often called "powerpointing". Just make sure you keep the main (reefed or full, depending upon apparent wind speed) flattened, centered and drawing smartly rather than flapping or backwinding. Unless you also have a nice flat jib that can be sheeted far inboard, it may not be possible to prevent the jib from flapping too much and you may have to haul it down or furl it. That's why a staysail, with a clew that can be sheeted in just as far as the clew of your mainsail, is the ideal companion for motorsailing.No matter what your final sail configuration is,however, you should not be heeling very much at all.Best of luck!Flying Dutchman

 

[Franklin]

57.33 true angle

Is what you get then you have 6 knots of true wind and you are doing 6 knots SOG. That comes out to a tacking angle of 116.66.

 

[Ross]

Franklin, And you measure this HOW?

*o

 

[Ross]

Rick, Engines can be run up to about fifteen

degrees out of level without harm. On my boat the admiral becomes dangerous at about twenty degrees of heel.

 

[Bill Roosa]

Vector math vs Cartesian math

I was only trying to make the concept simple. you are of course correct in your Cartesian approach but that still does not make the vector math wrong. I suppose I'll have to go get a software program to make the little bars over the vectors to make some of you happily butApparent wind vector (length and direction) = boat vector (length and direction) + true wind vector (length and direction)This is how you graphically solve for true wind by working the vectors and not the angles and good old pathorigus.

 

[Bill Roosa]

Perhaps I am willing to sail slower

to point higher to get there without so much tacking.Your fancy program does indeed indicate that tacking should take more than twice the apparent wind angle and I believe that in principal but it assumes you are racing. I don't like going to weather in rough seas and certainly don't want to race.Think clew between the mast and shrouds and you get the idea.

 

[Franklin]

measuring...I cheated

(http://www.sailingusa.info/true_wind_calculator.htm)

 

[Moody Buccaneer]

Good points ...

Bill makes some good points about sheeting angles.Most production cruisers can use a 10-12 degree sheeting angle. This puts the lead for a 150% Genoa inboard of the rail on most boats. If the track is parallel with the centre-line of the boat the sheeting angle gets wider as the sheet block is moved forward. If the same track is used for all sails, the 150 will point well, the 120-135 (rolled 150) will have a wider sheeting angle and will not point well at all.In heavier air, with a 100% jib up most boats like a sheeting angle in the 12-14 degree range. Bill is absolutely right that the proper lead of a jib should probably be inside the shroud base.On most masthead rigs, it makes more sense to leave the 150 out and double reef the main than to leave the main up and reef the Genoa. The 150 with a double reef should reduce heel and not give up pointing ability. It should also reduce weather helm more than leaving the main up and rolling the Genoa.Since we're not racing, motorsailing with just the main up is probably the most comfortable way to get upwind for many cruisers. IMO the ideal would be to change down to a 100% (or smaller) jib, but many cruisers are not setup to make this easy at sea.On a passage in open water, I'd look for the combination of sails and trim that gave the best ride and not be too concerned about how long it will take to arrive.Many times, one tack will be much better than the other. If the wind is forecast to die down I'd probably choose the "bad" tack at first and save the "good" tack for later when the wind is lower and the sea is still up. Same for a building wind, sail the "bad" tack first and save the "good" tack for later when the sea is rougher and the wind higher. Unless you think that sailing the "good" tack first will get you close enough to greatly reduce the time motorsailing on the "bad" tack.If one tack will take you out of averse current, take that tack first. If the current is with you, the chop will be worse, but the current is helping you along. You can reef and reduce heel enough to smooth the ride and still make good speed on your course.Hand steering and getting "in-sync" with the wave pattern also helps.Anyway you look at it, 50+ miles upwind is a long day sailing. Builds character though ...

 

[henkmeuzelaar]

a few more tacking strategies

With apologies to the original poster for getting a bit OT, I would like to add three more tacking strategies to Moody's highly informative list.(1) If you expect the wind direction to change, tack into the future wind direction first. In Vanuatu the SE tradewinds tend to back 10-20 degrees more into the East during the afternoon, so we try to make our Easting in the morning and then, with a little luck, shoot for the harbor on a long Southerly tack in the afternoon.(2) If conditions are variable and difficult to predict (e.g. with nearby frontal systems), don't commit yourself to long tacks in either direction in order to avoid finding yourself "stranded" way outside the original rhumbline.(3) When having to tack into a narrow reef or harbor entrance under rough conditions, with often hard-to-estimate leeway and current factors, keep enough distance off to deliberately short-tack by a mile or so, then carefully examine your recorded GPS track and calculate your final set of tacks. Fair winds;Flying Dutchman

 

[tom]

120 degrees true

Should have stated that I end up tacking through 120 degrees true not apparent. I am limitedin my sheeting angles since the shrouds are near the toe rail. Maybe I could rig something inboard. My other limitation is 4.5' draft. I will try to use a bit fatter sail triming to increase the sail's power.But realistically if waiting or changing destinations is possible that will be my preferred options. I really hate motorsailing....kind of an oxymoron!!!! My boat has a masthead rig and performance really sucks without a head sail. My old fractional rig did much better with main alone. Probably the single best thing I can do is buy new sails as they are over 10 years old. he sailmaker said that they were fine for cruising but a little out of shape for racing.ThanksBTW. My grandson and I had a great sail saturday. Sailed 25 miles or so . The autopilot stopped working and he steered the boat while I raised and lowered the sails. He did something that my wife can't consistantly do. After I dropped the sails I said head towards the marina. Without a word he pointed the boat directly at the marina about a mile away.....he is 5 years old!!!!

 

[Moody Buccaneer]

Jib ...

One answer for outboard shrouds is to limit your sail inventory. A 150 or 155% Genoa should have a decent sheeting angle. The shrouds and spreader sit in the belly of the sail close to the maximum draft.A 100-110% Jib should sheet inboard of the shrouds if you expect the boat to point well.All the sails in between the 150 and the 100 won't point worth beans on a boat with a wide shroud base. The spreader is too close to the leech of the sail and forces the sail to twist off too much for good pointing. With a high clew, they can be great power reaching sails, but they are rotten upwind.If you are thinking about new sails, have your sailmaker out for a daysail. Let him/her make trim suggestions and recommend which sail you should replace first ... you might be pleasantly surprised.

 

[RichH]

Sheet angle of jibs ....

is quite dependent on wind velocity. Once a boat is set up 'perfectly' for a close hauled course ... then and only then does one barber haul or start to bring the fairleads inboard. You do this only by watching or computing VMG ... or you can easily get 'carried away' in pulling a jib clew to the centerline. If you blindly bring-in the clew in towards the center line .. you essentially 'choke' the 'slot' .... which are very BAD terms aerodynmically speaking but there is is a specific limit where all ability to 'point' where the upwash of the mainsail does hardly affect the jib. You do this 'barber-hauling' ONLY if it increases VMG as its too easy to point higher into an inefficient 'pinch'.