Centerboard v Daggerboard

    Answers that make sense, thanks.

I've noticed how much more efficient the rudder is when planing, like twice as fast 3 times more efficient (at a guess). So, more wind the faster the boat the less daggerboard needed, less lateral resistance, less healing, less correction from the rudder, faster the boat goes, Win race, bruised wotsits. Hey but who cares finished with them anyway   + with daggerboard up it's easier to push out on the wire. I could always wear a box, now that would impress under a wetsuit.

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Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Topic: Centerboard v Daggerboard Posted: 12 Jun 07 at 3:27pm
	Answers that make sense, thanks. I've noticed how much more efficient the rudder is when planing, like twice as fast 3 times more efficient (at a guess). So, more wind the faster the boat the less daggerboard needed, less lateral resistance, less healing, less correction from the rudder, faster the boat goes, Win race, bruised wotsits. Hey but who cares finished with them anyway + with daggerboard up it's easier to push out on the wire. I could always wear a box, now that would impress under a wetsuit.

redback Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 16 Mar 04 Location: Tunbridge Wells Online Status: Offline Posts: 1502	Post Options Post Reply Quote redback Report Post Quote Reply Posted: 11 Jun 07 at 11:11pm
	What they are all saying also seems true in my experience. Raise the board raises the "centre of lateral resistance" and thus reduces heeling, and secondly the faster you go the less board you need. So raising it is good when its windy but a dagger can get in the way when raised and is impossible to move when loaded so we rarely move ours even in a 6 (Laser4000). When I sailed a Laser in which it is easier to raise I found it very usefull and I had a bit of a reputation as being a bit fast in a blow. So too, many years ago in the Scorpion, which had the additional advantage of moving it aft and decreasing any tendency to weather helm.

Calum_Reid Send Private Message Find Member's Posts Groupie Joined: 09 Apr 04 Location: United Kingdom Online Status: Offline Posts: 59	Post Options Post Reply Quote Calum_Reid Report Post Quote Reply Posted: 11 Jun 07 at 9:58pm
	That and the faster you go the less foil you need to have the same effect.


I luv Wight Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 28 Jan 05 Location: United Kingdom Online Status: Offline Posts: 628	Post Options Post Reply Quote I luv Wight Report Post Quote Reply Posted: 11 Jun 07 at 9:46pm
	It depends if it's a stuffing boat ( eg laser ) or a footing boat ( 'skiff' types ). For the footers it's most important to keep flat, and keep speed on - so a lifted daggerboard upwind in a breeze to reduce heeling moment is fast, and pointing is also not so bad when you are going fast. The stuffers will go even more sideways if the board is lifted. And downwind the skiff types don't move the board position. - max heeling moment is good with an asymmetric kite. Edited by I luv Wight
	http://www.bloodaxeboats.co.uk Andy P foiling Int Moth GBR3467 Freedom 21 Codling

m_liddell Send Private Message Find Member's Posts Really should get out more Joined: 27 May 05 Location: United Kingdom Online Status: Offline Posts: 583	Post Options Post Reply Quote m_liddell Report Post Quote Reply Posted: 11 Jun 07 at 6:39pm
	There was a test done with evenly matched lasers written about in the lasercoach CD-ROM. The laser with the board fully down came out ahead by a decent sized margin.

English Dave Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 10 Aug 06 Location: Northern Ireland Online Status: Offline Posts: 682	Post Options Post Reply Quote English Dave Report Post Quote Reply Posted: 11 Jun 07 at 4:20pm
	Ok, if you cannot keep the boat flat the daggerboard only presents: Length daggerboard x cosine(angle of heel) to the water. The sail area presented to the wind reduces similarly. In addition, because you are heeled, the corrective rudder action slows the boat as well. So do whatever it takes to keep the boat upright. The only problem I see with a L2 is than the hull is so flat that the daggerbvoard is presenting pretty much all of the boat's lateral resistance. So it may be very height/depth sensitive. Don't worry about your wotsits. Just make sure your twigglet is kept out of harm's way. Seriously, given the restricted amount of cockpit space on a L2 you may find that trading ultimate boat speed for ease of sailing (ie not castrating yourself on the daggerboard rope) makes for faster round the cans in the long run. An entirely different take on VMG!
	English Dave Ballyholme Yacht Club (You'd think I'd be better at it by now) Hurricane 5.9 SX RS700

HannahJ Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 23 Jul 05 Location: United Kingdom Online Status: Offline Posts: 861	Post Options Post Reply Quote HannahJ Report Post Quote Reply Posted: 11 Jun 07 at 4:15pm
	Just a couple of inches would probably be enough, and it really does help.
	MIRROR 64799 "Dolphin" The pessimist complains about the wind; the optimist hopes it will change; the realist adjusts the sail

JimC Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6662	Post Options Post Reply Quote JimC Report Post Quote Reply Posted: 11 Jun 07 at 4:09pm
	Lifting the daggerboard does help when seriously overpowered. The limiting factor is keeping enough area that you don't stall the plate coming out of tacks, plus room in the boat - if you trip over it on every tack and fall in that's not fast either!

Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Posted: 11 Jun 07 at 4:05pm
	When racing our L2 we observe the basic rules about daggerboard height, right down for the beat, half way for reaching, maybe up a bit more for the run adjusting to eliminate excesive roll. Just been reading "crewing to win" and Andy Hemmings talks about raising the centerboard on a beat if it's really windy. the 2 reasons he gives for this are, the center of drag moves aft in line with center of effort making it easier to steer, it also reduces the risk of tripping in gusts, small sacrifice in leeway for the sake of an upright boat (a 505 in his case I think). He gives no advice for daggerboards. Obviously there is no advantage regarding for and aft drag but what would the panel advise for daggerboard height on a gusty beat with sails depowered to the max when youre hard pushed to keep the boat upright,,also any other tips on daggerboard adjustment. Sorry if this appears to be a daft question but still new to the sport and when I crew I keep catching my wotsits on the dam thing .....Thanks.