It was quite puffy today probably a good force four on the sea of joy which translates to 2 - 4 inland, so off wind (which it never seemed to blow choosing only to puff up on the upwind legs)I left the kicker on, so I'm wondering if it had a contributory effect on the side to side roll that once started engages a life of its own.

So what's the story, it's tedious I don't want it to happen, fix it someone.

It's a downwind leg the boat starts rolling from side to side, it hasn't anything to do with gybing it's just some sort of speed wobble, I used to think it was to do with wave action in the Blaze, this is a billiard table, it's got to do with the leech of the sail I'm sure of it.

or, squat down in the middle of the boat, tuck your head under your arse and kiss it goodbye... 

The tendency is to be react by moving weight to counterbalance but you can't be quick enough - so you tend to be out of phase increasing teh oscillation.

Finally at extreme angles of heel the rudder will work in a horizonatl (or part horizontal) plane not a vertical one.  So when you head up to correct the bear away it pulls the boat to windward too.

So what should you do:

Use more kicker(may not be fast of it depowers you be bending teh mast).

Sit more still - you can't beat the oscillation.

Sail in a safe by the lee fashion with stable reversed airflow from leech to luff.  (Often fast)

Sail in a stable broad reaching position.

Use a combination of the two to achieve your required heading.

When you roll to windward do not try and head up to correct.  Instead of pushing the tiller, pull it, thus pushing the boat flat with the rudder.

Finally buy the Rooster Downwind Sailing DVD.  Better than borrowing it because all thought it will cost money and you will feel a bit dirty, no one will know.  It shows it all really well.

Also, board down to go with kicker on and sheet in a bit.

Got to say that I always thought it was more to do with the rig accelerating faster than the hull and in so doing it caused the sail to lift, tilting the mast to windward. You counteract it and the rocking started. When I started in lasers in would rock you about 3 time before you went swimming but once I got better it seemed to be down to one. 

As the gust hits sheet in a bit and as long as you are not running by the lee this will depower it. If you are running by the lee you will need to steer into it (I think) to get the flow of the wind over the sail rather than into it.

If you apply too much kicker the end of the boom is going to hit the water pretty damn quick in the gybe and you'll swim. If you have too little then even if you pull the main in the top of the sail is twisted and still presents itself square to the wind and in so doing still generates lift and movement of the mast to windward. 

My version is not a master class at all, and Steve DVD will show you how to do once you have mastered the getting along safely but slowly method I have suggested, but it is somewhere to start you and hopefully stop the death rolls that may put you off

So, I already had a fair amount of kicker on, not an awful amount because it had been quite puffy up wind and I'd de powered a bit with downhaul, that of course could have been a contributory factor, if the downhaul did let the top of the leech twist off a bit, which tbh it didn't appear to.

I get the sheet in a bit, that's what i used to do with the Blaze, but it slows you down, then again so will death rolling right in I guess. The boom digging in isn't the issue it is on other boats, it's quite a high boom the racks go in before the boom does, and that's a whole other can of worms I bet.

I can only see it being a really serious problem in a force five and above and I'm seriously thinking of trying for the smaller sail for the winter, I was already racked out five holes, not sure how many more knotches there are.

Has anyone tried standing up to stop that rolling about? Just a thought.

The only issue, there's not much to hold onto, the wiggle stick doesn't provide much counter balance to the mainsheet, which is the only other stabilising do dah to hang on to, it does feel more natural though, but as you point out you do feel a bit 'rock star' tall poppy when all about you are seated.

Would it in itself counter that death rolling though, I seriously doubt it, sheeting in does sound the best answer I've read here...

Sheeting in is only one part of this equation - and its slow.  And unless used at the right time in the right way may still make things worse.

[tube]http://www.youtube.com/watch?v=hEQttj8E1b0[/tube]

And that other bit is wave surfing so not the same, I get that, can do it a bit on the sea, it's easier, more predictable if there are waves involved.

This was unpredictable without the benefit of an up slope of a wave to 'check' on.

I clearly have been running before walking having only really spent much time on spinnaker driven off wind boats, except the Blaze which from memory wasn't quite as 'lively' off wind. Lively in a good sense, the EPS certainly appears to accelerate quicker than I remember my Blaze doing, then I never sailed it in the close confines of a lake where everything seems to happen faster.

Oh and the EPS has I guess what you'd describe as semi stayed rig, the lower section has a forestay and lowers, to about 2-3 ft above the deck.

Oh and another thing, you don't seem to see the Phantom doing this much, can't say I've noticed my chum (another ex racing windsurfer) having death roll issues, then he is a bit heavier.

And Maxi, yep, the point of posting that wasn't for Graeme to start copying them, it was to highlight that an induced 'death roll' is actually fast in the most competent of hands.  As an ex laser sailor, you've probably experienced the upside of a fortuitous death roll survival... a shed load of speed and exceptional VMG to the mark on a dead downwinder.  Of course being able to initiate this and know you'll survive it, control it even... well that's a skill I never mastered 

Yes it has an edge to edge curve as well as a nose to tail parabolic rocker with what looks quite close to a shift to flat that we use windsurfing, sailed flat it really is as 'quiet' a wake as you could wish for, it doesn't like to be on its ear and all that rocking is not good news. The obvious answer is never dead run but then on a lake with a short buoy to buoy course, comes the time you have to point right at them and should that coincide with a shift.....

You don't get death rolls with kites, well not that I've ever experienced it seems to be the province of certain single handers, I bet that 300 would get five stars if ever death rolling were in the michelin catalogue.

4.5... the reverse flare gives some crucial face saving opportunity... if you're alert (or have exceptional fitness )

It probably only has been in my case since I've only ever experienced assyms that are loaded to one side come what may.

It also occurred to me, the longer and lower the boom the more likely it must be, although I've not seen boats like Contenders engage in the habit, then they have flatter hulls.

 

The 300  may occasionally heel a bit to windward on a run in a blow, but so will any boat sailed incorrectly - the 300 just tells you quicker than most boats.

 

As Sargesail mentioned, there is more than one way to get downwind safely. I love this picture as it's all there - http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013673.jpg - http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013673.jpg

 

Sargesail is in 506 - bit of kicker, boom well out, rock steady. I'm in 411, bit less kicker, boom in a bit more, rock steady. The thing in commom is that both of us have the top batten in line with the mast. Letting the top batten go in front of the mast is what causes death rolls -  http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013590.jpg - http://www.chunkypics.co.uk/photoalbum/Sport/Sailing/2007/RS300%20Inland%20Champs%2001-12-07%20NSC/Saturday/Page%202/E5013590.jpg

 

 

Now I look at that and see a badly designed craft, low nose volume going under in no waves to speak of.

You lot would all go on about it being a technical boat to sail and that fella is obviously doing it wrong, when patently he's not, the conditions are blowy enough for it to be fun, not a battle.

And the more you lot get blinded by that 'technical to sail' rhetoric, the more your sport will disappear to the margins.

The 300 sailors (and ex-300 sailors) and a few others have told you how to solve your problem - you seem to know better, and then you sl*g off our craft.

And the stuff above is part of the fun.  And although Steve would tell you that his brother Nick is doing it wrong, I remember this moment: Nick didn't swim - which indicates just how wrong you are about the nose volume.

And I don't see my sport disappeearing to the margins other then in your head.

But one is in my mind a far better boat than the other, naturally we're going to disagree.

And as to knowing better, if I knew better I wouldn't have posted asking now would I?

And frankly I'm still not really any better off given all the variables.

The way that I look at this is that there is a sector from a broad reach to dead downwind that is a problem because the air flow over the sail becomes unstable. This means that in the light it is slow to sail in this sector and when its windy the boats behaviour becomes unpredictable leading to death rolls or broaches. So I always avoid this "no go sector" and sail either on a broad reach or bye the lee. If I have to move through this sector I do it quickly. This works for me and the 2 angles give lots of tactical opportunities on the race course. The sail set up for the 2 modes is slightly different with less vang being favourable for the BTL sailing.

- I find its much easier to let of the cunningham but keep some kicker on. 

- also when the boat starts to heel on top of me I sheet in the mainsheet about 1.5 or 2 armfuls and move my weight slightly into the middle and then ease it out :)

sometimes the best thing to do can be to gybe :)

 

 

Sorry GRF but you really would benefit from borrowing/buying the downwind dvd http://www.youtube.com/watch?gl=UG&feature=relmfu&hl=en-GB&v=JivVDWlNiaw - http://www.youtube.com/watch?gl=UG&feature=relmfu&hl=en-GB&v=JivVDWlNiaw .  Really explains how to stop the deathroll (and use it to your advantage).  Plus, you get to watch Lasernut capsize , as he briefly features in the DVD, which is always a giggle

 

If you really can't stomach rooster than I think http://www.caribwind.com/ltc/laserdvd/ - http://www.caribwind.com/ltc/laserdvd/  also includes footage/tips downwind (its a little while since I watched my copy) and I think you know the guys running the centre so should be able to get hold of a copy.

 

I used to coach when I sailed at NSC, let all my RYQ quals lapse since moving south however.  Now just run the occasional laser training session with Lasernut at HHSC.