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These roll tack thingies..

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    Posted: 11 Dec 17 at 8:22am
Originally posted by mozzy

What sort of hull shape would require windward heel on the entry? 

Try comparing a Scorpion and an RS200. The big thing to deal with in a Scorpion is the hard chine on the hull. Windward heel on entry is less important than other things. However the right amount of leeward heel immediately reduces wetted area in a flat calm. In contrast in an RS200 it feels like the only thing we can do to unstick the boat from the water is to dig the bow in.

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Post Options Post Options   Quote mozzy Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 1:49pm
Originally posted by iGRF

that's as much about red mist with the damn top batten not transitioning..
Battens are a pain! In medium wind a pump of the main can be okay but the best option is a tug on the downhaul, especially in the light. If you have a crew, have them do this as you gently pull the boat flat. 

Originally posted by iGRF

So it obviously does matter where the rig is into the tack so should you leave it close hauled in and maximise the rocking momentum or should you sheet out a bit more than you normally might in order to maximise the inward sheeting combined with the roll back to weather?

In light winds you just have to be more patient. The forces all work the same way, you just have to wait for them to do their work. You're going slower through the water, so you're just going to have a slower rate of turn. 

Put (more) leeward heal on  squeeze on the main and be patient. Wait for the boat to round up then as the sail starts to stall slowly pull it on top (this will create apparent in the rig and keep teh sail driving through the tack). Hold the tiller loose and just let it follow the turn. 

Give plenty of ease on the exit and pull the boat up right very slowly. 

One thing you see a lot of people do in light winds is put a too aggressive pump in. You get the same amount of energy back (via increased apparent at the top) whether you pull the rig back upright quickly or slowly. But if you pull it too quickly you loose energy stalling the sail (detaching the flow), and the same happens for the foils below the water.  




Edited by mozzy - 04 Dec 17 at 2:05pm
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 1:45pm
Originally posted by 423zero

I have a simpler interpretation, whichever way you heel it turns the other way, opposite to a bike.

Exactly and why I like to heel the boat to leeward in these sort of conditions, this was another time in similar circumstance, so to go from there into a tack I obviously have to duck under the rig rather than the sensible way of walking round the front, but this inevitably initially rocks the boat the wrong way as my weight comes off the leeside.

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Post Options Post Options   Quote 423zero Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 1:29pm
I have a simpler interpretation, whichever way you heel it turns the other way, opposite to a bike.
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 1:29pm
Well given in the kind of light zephry type conditions I'm talking about there is very little 'pressure' from the rig and lets be honest the momentum both into and out of the tack is kinetic and this is the bit I'm doing wrong, being far to aggressive apparently but then that's as much about red mist with the damn top batten not transitioning..

So it obviously does matter where the rig is into the tack so should you leave it close hauled in and maximise the rocking momentum or should you sheet out a bit more than you normally might in order to maximise the inward sheeting combined with the roll back to weather?
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Post Options Post Options   Quote mozzy Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 12:31pm
I get that hull shape can make a boat turn. But I don't feel it is more important than the where the rig is in relation to the hull. 

Also, don't all hulls flare in such a way that they head you up when heeled to leeward? In which case this would be another argument in favour of leeward heel on the entry. 

What sort of hull shape would require windward heel on the entry? And if that hull shape reacts well to windward heel when heading up on entry to a tack, why don't the sailors use windward heel when heading up in other situations, like the leeward mark? Or leeward heel at the windward mark? 

You don't see firefly (an example of a class which favours windward heel on entry) sailors heeling the boat to windward as they round up at the bottom mark, so why do it going in to a tack? 




Edited by mozzy - 04 Dec 17 at 12:35pm
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 12:22pm
Originally posted by JimC

Originally posted by mozzy

I'm not convinced it is hull shape is the main factor which is turning the boat with heel,

depends on the boat, some hull steer enormously, others much less so.


This is true, a lot depends on the stern shape, an RS200 must be a bloody nightmare...
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Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 12:15pm
I know about footsteering things without rudders and get immense grief down the lake everytime I stand up to get the damn thing to heel to leeward at the end of a little puff. Also downwind they don't like me stood up making 'corrections' using my weight rather than the rudder. It's natural to me, you can't eradicate forty years of footsteering and these sitty down things need a lot more pressure to make them do what you want.

They work like boards as you would 'flare' rather than 'carve' gybe the difference being turning with the plate down or up which requires pressure on the opposite side to the other. i.e. windward side with the plate down, leewood side if the plate is up, so I get all that.

The bit I can never fully get is the amount of leverage to apply on the sail via rope and always end up reverting to holding the boom to get the right feel, but, 'they' don't like me doing that much either and I'm constantly watched like a hawk for 'illegal' moves.

Now 'they' are a particularly good couple of females who sail rings round me in their Miracle in any wind and they seem to have a better 'feel' obviously born of experience and ability to trim their rigs conventionally in iffy wind. What with them and a the bloody green ghosting solo my sunday morning has once more been ruined just as I thought I'd returned the natural order of things to the universe with an earlier win.

Oh and thanks for all your help I've read it all and some of it does occasionally sink in..

and apologies for putting it in the wrong section, not on it at the moment, think it's early onset man flue..

Edited by iGRF - 04 Dec 17 at 12:20pm
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Post Options Post Options   Quote mozzy Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 10:48am
Here's another video... good exercise to practice tacks too. Some of the tacks are okay, some not great. 



I'll remain sceptical that different hull shapes being the main driver in dinghies turning with heel until someone can show some good evidence. 
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Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 04 Dec 17 at 9:53am
Originally posted by mozzy

I'm not convinced it is hull shape is the main factor which is turning the boat with heel,

depends on the boat, some hull steer enormously, others much less so.
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