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Light wind trim |
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snowleopard
Groupie Joined: 02 Oct 17 Location: Cornwall Online Status: Offline Posts: 66 |
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Topic: Light wind trim Posted: 15 Mar 18 at 1:59pm |
Regardless of the number of hulls, at very low speeds, skin friction is more significant than waterline length or hull form so altering the trim of the boat to reduce wetted surface does help speed. In cats, there is less opportunity than monos but moving forward to lift the stern clear of the water does help. At what speed you stop doing that is a matter for experimentation.
I remember competitive Laser sailors sitting forward of the mast to lift 3 ft or more of the stern clear of the water in ghosting conditions.
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One hull good, two hulls better.
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kfz
Groupie Joined: 02 Nov 10 Location: UK Online Status: Offline Posts: 96 |
Post Options Quote Reply Posted: 01 Dec 10 at 10:02am |
oops
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alstorer
Really should get out more Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899 |
Post Options Quote Reply Posted: 01 Dec 10 at 9:37am |
kfz- this is the multihull section!
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Al |
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kfz
Groupie Joined: 02 Nov 10 Location: UK Online Status: Offline Posts: 96 |
Post Options Quote Reply Posted: 01 Dec 10 at 9:35am |
Depends on how light the wind is. Very very light winds where your struggling to fill the main I tend to get the crew on the leeward side and get the boat healing just a little, Its holds the boom out and helps the sail get some sort of shape. Vital theres virtually no kicker, though I have experimented with using a little outhaul lately.
Once you have enough wind to hold the main shape then whatever side holds the boat dead level. Let the outhaul off and get the slack out the kicker.
Not sure if this is right or not. |
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Wee Man
Far too distracted from work Joined: 24 Aug 06 Location: United Kingdom Online Status: Offline Posts: 214 |
Post Options Quote Reply Posted: 18 Oct 10 at 8:52pm |
Mainly noticed the different style upwind, I was wondering if it has anything to do with the different bows on the newer boats (Wild Cat, Edge, Infusion).
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zailor
Far too distracted from work Joined: 10 May 09 Location: Penparc Online Status: Offline Posts: 249 |
Post Options Quote Reply Posted: 18 Oct 10 at 8:09pm |
so was that windward or leeward heel?^
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Black no sugar
Really should get out more Joined: 04 Dec 04 Location: Somewhere between Brighton and Lancing Online Status: Offline Posts: 3941 |
Post Options Quote Reply Posted: 18 Oct 10 at 7:41pm |
It's only a Topper tale so feel free to ignore. During the summer, we were two Toppers side by side on a broad reach / run in light wind. We were both on a starboard tack with me on the outside, trying to get faster. We sailed most of that leg at the same speed. Thinking I'd had enough, I assumed the monkey position (holding on to the daggerboard, leaning to starboard, as good instructors teach) and I was surprised to see how much quicker the boat went. I pulled away from the other boat really quickly, considering the wind strength.
In your question, you don't mention the point of sail so this answer is probably... pointless! Edited by Black no sugar - 18 Oct 10 at 7:42pm |
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mattmd
Posting king Joined: 23 Mar 09 Location: United Kingdom Online Status: Offline Posts: 151 |
Post Options Quote Reply Posted: 18 Oct 10 at 5:11pm |
When I sailed F18, On lightwind days id crew, by sitting on the leeward side,
this is because it would lift the windward hull and reduce wetted surface area, and consiquently go faster. But just getting your weight forward helps speed as it stop the transom from digging in. But I personally would sit on the leeward side, however be carefully if your sailing somewhere gusty, be ready to run over the other side if it heels massively, gain speed from gusts do not pinch. Hope this helps
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Matt MD
Contender GBR-620 |
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Wee Man
Far too distracted from work Joined: 24 Aug 06 Location: United Kingdom Online Status: Offline Posts: 214 |
Post Options Quote Reply Posted: 18 Oct 10 at 1:08pm |
Having just come back from Grafham.
On the light wind day I noticed some crews lying along the leeward hull forward of the beam, while some others lie along the windward hull. Which is fastest? and why?
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