29er GBR 074 Tynemouth |
Laurent Giles 'Jolly Boat' Exeter |
J24 (Sail No. 4239) Dartmouth |
List classes of boat for sale |
Pointing-so whats that all about? |
Post Reply | Page 123 4> |
Author | |
Oatsandbeans
Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382 |
Post Options
Quote Reply
Topic: Pointing-so whats that all about? Posted: 21 Dec 17 at 6:17pm |
Following on from a good thread on the Star event. It was mentioned how high they
point . So why is that? What makes some boats point and others don't, and how can some sailors get boats to point higher than the rest? |
|
Guests
Guest Group |
Post Options Quote Reply Posted: 21 Dec 17 at 6:41pm |
The angle at which a boat points is the sum of its aerodynamic and hydrodynamic drag angles. Drag angles are the arctan of lift/drag ratios. So, better lift/drag ratio = higher pointing. Given that lift is largely limited by righting moment, the best way to improve pointing is therefore to reduce drag - of the underwater and above water parts.
|
|
Oatsandbeans
Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382 |
Post Options Quote Reply Posted: 21 Dec 17 at 6:47pm |
Thats really good but your average sailor can't deal with that. How does he get his boat to point higher than his mte off the line, when he is using the same gear? Should he have a fuller sail faltter sail, sheet the jib more or what?
|
|
Do Different
Really should get out more Joined: 26 Jan 12 Location: North Online Status: Offline Posts: 1312 |
Post Options Quote Reply Posted: 21 Dec 17 at 7:19pm |
To a large extent I've given up worrying about pointing in isolation. My biggest concern now is to stay fully powered, driving and bolt upright.
Edited by Do Different - 21 Dec 17 at 7:20pm |
|
Oatsandbeans
Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382 |
Post Options Quote Reply Posted: 21 Dec 17 at 7:29pm |
I get that but being able to point higher than the rest can make life a bit easier. Getting off the line you can burn off the guy on your hip and get a clear lane. At the leeward mark you quickly get your own clear air as you are sailing higher than the rest. You end up being able to sail your own race in clear wind. So that can't be bad.
|
|
iGRF
Really should get out more Joined: 07 Mar 11 Location: Hythe Online Status: Offline Posts: 6496 |
Post Options Quote Reply Posted: 21 Dec 17 at 7:32pm |
Pointing high 'off the line' is more a matter of having your nose ahead. Because if the boat immediately downwind of you gets his nose ahead of you, you can have the best set up rig in the world but overcoming the heading effect of the wind as it channels between you and he will be difficult to overcome (Another lee bow effect)and you will slip back, then the boat above you will also overwhelm you and you're back into the 2nd rank.
So, 1st rule start on time, in fact, start a micro second ahead of time. I point really high, always have, can't help it I'm a lightweight, it's my style. I often wish I didn't because it is not always the fastest method of sailing, there are times when cutting loose and sailing fast and free works better, but how do you do it, we have an expression where the head looks, the body will follow, so hanging outboard looking upwind plenty of body twist, I have found exported from my windsurfing technique, seems to apply to dinghies. I picked up on it by following an ex Olympic squad lady in a Europe and Jesus she could point high and she nailed every shift. So for me it was following someone really good and emulating the way they sail. Edited by iGRF - 21 Dec 17 at 7:34pm |
|
Oatsandbeans
Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382 |
Post Options Quote Reply Posted: 21 Dec 17 at 7:40pm |
Yes its tricky if the guy to leeward has his nose in front, because then you are sailing in a header from the"lee bow effect", but if you can hang in which will inlvolve getting dropped back a bit you may then be able to climb up if you have sussed out how to point. and then can work out to windward and could finally come out on top.
|
|
Guests
Guest Group |
Post Options Quote Reply Posted: 21 Dec 17 at 8:24pm |
Clean hull, good slot gasket, foils well maintained and aligned as per design intent. Boat upright and well trimmed, sails flat and slot small (jib sheeted about 9-10 degrees). I don't think there is a magic bullet, just lots of increments gains to be had to reduce drag.
|
|
Oatsandbeans
Far too distracted from work Joined: 19 Sep 05 Location: United Kingdom Online Status: Offline Posts: 382 |
Post Options Quote Reply Posted: 21 Dec 17 at 8:34pm |
So its all about drag- so do you need full sails or flat sails?
|
|
423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 21 Dec 17 at 8:48pm |
I was told by one of our old sailors, get well forward, dig the bows in, heel to windward for better gust response.
Never done me any good though.
|
|
Post Reply | Page 123 4> |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |