speed difference between tacks
Printed From: Yachts and Yachting Online
Category: General
Forum Name: Beginner questions
Forum Discription: Advice for those who are new to sailing
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=5562
Printed Date: 26 Jun 25 at 9:10am
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: speed difference between tacks
Posted By: ellistine
Subject: speed difference between tacks
Date Posted: 01 Jun 09 at 9:43am
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Why is it that when your sailing into the wind and
steering to the telltales that sometimes the boat travels noticeably slower on one tack than the other? I'm not on about racing to a mark but just sailing into the wind. I suppose it could be a tide thing but would you actually notice the tide in middle of Portland Harbour? I hadn't considered it as being tidal. |
Replies:
Posted By: Jon Emmett
Date Posted: 01 Jun 09 at 11:00am
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You are probably more lined up with the chop on one tack than the other.
------------- http://www.amazon.co.uk/Be-Your-Own-Tactics-Coach/dp/0470973218/ref=sr_1_1?ie=UTF8&qid=1312565831&sr=8-1 - |
Posted By: ellistine
Date Posted: 01 Jun 09 at 11:16am
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Possibly. I'll have a look at that next time.
Presumably it has to be the water or the boat, there's nothing odd about the wind that I don't know about? It seems to happen downwind too with the kite up. You can be drifting along going nowhere and then throw in a jibe and your off! ------------- |
Posted By: JimC
Date Posted: 01 Jun 09 at 11:39am
That's almost always tide... |
Posted By: Jon Emmett
Date Posted: 01 Jun 09 at 11:53am
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There are always pressure difference/current dfferences... The faster you are going the sooner you will get into the different conditions.
------------- http://www.amazon.co.uk/Be-Your-Own-Tactics-Coach/dp/0470973218/ref=sr_1_1?ie=UTF8&qid=1312565831&sr=8-1 - |
Posted By: Scooby_simon
Date Posted: 01 Jun 09 at 11:58am
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Tide would be top of the list Are your shrouds the same length and thus mast vertical? Mast bent? ------------- Wanna learn to Ski - PM me.. |
Posted By: ellistine
Date Posted: 01 Jun 09 at 12:00pm
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Jon, you've spent a lot of time in Portland Harbour,
what tidal effects are typical there? I perhaps wrongly assumed it would only really be noticeable near the entrances and perhaps near Ferry bridge. ------------- |
Posted By: Jon Emmett
Date Posted: 01 Jun 09 at 12:11pm
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Eeek equal shroud length that is a whole can of worms... bent foils etc. etc. The tide in the harbour is significiant and not really something I could get into in a forum post! ------------- http://www.amazon.co.uk/Be-Your-Own-Tactics-Coach/dp/0470973218/ref=sr_1_1?ie=UTF8&qid=1312565831&sr=8-1 - |
Posted By: ellistine
Date Posted: 01 Jun 09 at 12:14pm
Doh. And I even bought your book  ------------- |
Posted By: Guest
Date Posted: 01 Jun 09 at 12:40pm
Probably going fastest on the tack which give you more sun  ------------- |
Posted By: ellistine
Date Posted: 01 Jun 09 at 1:15pm
This Sunday it was more a case of which tack gives you the most cooling breeze! ------------- |
Posted By: ChrisJ
Date Posted: 01 Jun 09 at 4:13pm
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Sometimes, the wind can get "stuck" in the sail: too much kicker / mainsheet tension / battern tension / fullness in the sail etc. You don't need much "too much" for the boat to be saiing slower than it could. Then you tack / gybe, and shake all the wind out, re-sheet, re-angle the boat, pick a wind shift, and get moving again. Happens ALL the time inland! |
Posted By: Hector
Date Posted: 01 Jun 09 at 5:46pm
| Sailing on a lift almost always feels better than a backer. |
Posted By: NickA
Date Posted: 01 Jun 09 at 6:38pm
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If it's ALWAYS faster on one side than the other then it isn't tide or direction of chop or "stuck wind" (really ???) surely. Probably different length shrouds or lowers (measure them & check which hole in the shroud plate they're in) or failing that a rudder that isn't hung quite vertical or a warped centreboard. Boat builders aren't always exact in their placement of cleats, blocks and fairleads either Anything that's not symetric could do it. Including your crew's legs probably! ------------- Javelin 558 Contender 2574 |
Posted By: Jon Emmett
Date Posted: 01 Jun 09 at 8:01pm
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I would disagree a tack where you are going straight into the chop is often slower than one where the chop is side on.
------------- http://www.amazon.co.uk/Be-Your-Own-Tactics-Coach/dp/0470973218/ref=sr_1_1?ie=UTF8&qid=1312565831&sr=8-1 - |
Posted By: Lukepiewalker
Date Posted: 01 Jun 09 at 9:57pm
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Rather than 'stuck wind', I would go with 'stalled sail'
------------- Ex-Finn GBR533 "Pie Hard" Ex-National 12 3253 "Seawitch" Ex-National 12 2961 "Curved Air" Ex-Mirror 59096 "Voodoo Chile" |
Posted By: ellistine
Date Posted: 01 Jun 09 at 10:06pm
I'll start to check but I don't reckon it's always a port or starboard tack that's quicker (ie boat problems). I'm pretty sure it varies. The Sunday just gone it was easier to keep the crew out on the trapeze one way than the other. It probably is the tide. Being new to sailing I've been ignoring it but I suppose I'll have to start paying attention to it. ------------- |
Posted By: Jon Emmett
Date Posted: 01 Jun 09 at 11:15pm
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If it was easier to keep the crew out on one tack than the other it may well be a pressure difference (sailing into/away from more wind). Tidal differences are still relatively gradual.
------------- http://www.amazon.co.uk/Be-Your-Own-Tactics-Coach/dp/0470973218/ref=sr_1_1?ie=UTF8&qid=1312565831&sr=8-1 - |
Posted By: hollandsd
Date Posted: 02 Jun 09 at 1:01pm
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sailing at hythe, i find that in certain conditions wiring is much easier on one tack than the other i found this was due to differing angle of the current pushing on the foil, if you get the current pushing the foils the wrong way then the boat feels awful, but if you get it right the gains that can be made are quite supprising.
------------- Laser 184084 Tasar 3501 RS600 698 RS600 782 |
Posted By: Garry
Date Posted: 02 Jun 09 at 5:34pm
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Checking your mast is straight is relatively easy, for one way look at: http://www.youtube.com/watch?v=cSyrc3QUssE - http://www.youtube.com/watch?v=cSyrc3QUssE - there is no sound worth listening to with this video clip. Garry ------------- Garry Lark 2252, Contender 298 www.cuckoos.eclipse.co.uk |
Posted By: winging it
Date Posted: 02 Jun 09 at 5:53pm
I'd agree with this - if you're sailing on a header you think there is enough wind to keep yourself out on the wire, but there isn't because you're always heading away from the pressure. Sailing in a wind bend can have the same effect. I am sure someone more scientific than me can explain it better. ------------- the same, but different... |