How to avoid rounding up whilst sailing downwind

surprised no-one has mentioned traveller? First I'd check main (or genoa) is'nt oversheeted then I'd dump the traveller, then flatten the main as much as poss (backstay,outhaul & cunningham) before going for a reef.
 
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flaming said:
Tip 3. Reattach the flow. Rudders work in two modes - with flow over them and when stalled. Actually I'll rephrase that. Rudders don't work when stalled... If you're heaving on the tiller and all you're getting is a lot of "breaking wave" noise from the rudder then your rudder has stalled, and turning the way you want to is not going to happen any time soon. Quickly push it back straight and then reapply the helm progressively. Think of this a bit like braking in a non ABS car.
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As a recovering fluid dynamicist, I endorse this message.

All aerofoils/hydrofoils, including rudders, stall about 20 degrees angle of attack. That means that they stop producing lift in any quantity and become simple drag devices, so a stalled rudder slows you down but doesn't turn you much.

Once the boat is turning the flow across the rudder is coming from one side, so you can put the helm over more without exceeding the 20 degrees AoA and stalling. The faster you're turning (ie rotating) the more helm you can use.
 
Pole out genoa on one side, main sail on the other side, run downwind but ONLY IF your are good at the helm (if there waves). If this is not an option set the boat, as many others have said, to "front wheel driving". Using just the genoa in other words. Or even using the spinnaker as "fantasia"said though you need to be brave to do this (personally I am not).
 
Selling it is not such a far fetched solution
We used to have a Bavaria that would round up like a Gaucho pony at any excuse and keep going round it felt that the boat heeled over onto its shoulder and the rudder stalled and felt that it came out the water
best day was the day it was sold.
The reality was that even when It did not round up wou were afraid it would , close sailing in races was to be avoided at all costs with the result that we never really competed.
 
maxmonk said:
Sailing downwind in a Beneteau First 305 on a very broad reach under full full main & genoa with about 15kts apparent. The main is all the way out (short of the spreaders) and everything is hunky dory. A few gusts come through of only about 25kts but with the main all the way out the centre of pressure is off to one side and they create a strong rounding-up moment that the rudder cannot control. Kicker off to attempt to spill the wind but still not controllable. I have traffic off to windward so rounding up is not desireable! Also makes it difficult to come onto the wind to reef.

Any thoughts on how best to manage the situation?
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Full sail, 25knot gusts over the deck singlehanded in a lightish 30ft boat is driving it very hard.
If you have traffic to windward and are afraid of rounding up, you can either drive it like a maniac until the wind drops, or reduce sail before the other boats get too close.
Round it up under control and get the main down, or a couple of reefs in.
It won't slow the boat that much.

IMHO any talk of poling the genny out while s/h is just wrong if you don't have much sea room.
 
Given that you are sailing (singlehanded) a modern flatbottomed AWB in 21-21kts true wind (F5), my advise would be to learn the capabilities of the boat. Generally with these types of boat, you should start reefing above a F4 which will not reduce boatspeed but will increase control and stability. Running downwind is the easiest point to be lulled into a false sense of security. As has been said above, reef and reef early but learn what the boat needs.

You could troll a few warps out the back maybe.....
 
flaming said:
…. Reattach the flow …… Rudders don't work when stalled … rudder has stalled, and turning the way you want to is not going to happen any time soon. Quickly push it back straight and then reapply the helm progressively. …..
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In the late 1970's I read about yachts on the Whitbread RTW Race. One comment that I have remembered from the article was about steering down big waves, which is sort of similar to this problem, too much power. They would waggle the wheel really quickly, over a small arc, to keep the water flow collapsing around the rudder so the rudder could maintain grip. IIRC the pedestal had gearing which could be selected to aid this. I have done this on a Lasers dinghy, surfing on big waves, a quick, short slap from side to side and control is maintained.
 
Our boat has a deep rudder and generally good directional stability but it is Finnish so has a very high aspect rig and a long boom. A potential customer who was mainly interested in racing ( I used to do demos. for the importer) brought sailmaker Chris Owen with him when he was test sailing on our boat. Chris said the boat was a bit over powered in gusts with its 140% genny and full main and suggested that the rudder would have more power if the leading edge was thicker, it is a Jefa racing foil section and only about 60mm. thick around the ss. rudder shaft. (He also recommended a battened blade jib which I later purchased from him, it has transformed performance in 20 kts and means I rarely need to reef, however two headsails means that I lose my roller reefing headsail allowance on CYCA).
He followed up the rudder mod. seeking some advice from a respected designer of race boats ( I knew the adviser by reputation but have forgotten his name,) the change in the whole rudder profile was regarded as too difficult to get right, but instead a fin was placed around it about 150 mm from the top. His client bought a Finngulf, and after a season they had Ardfern boatyard modify his rudder. After a year racing in his clients boat, Chris confirmed that the mod. was effective so I did it to mine the next winter. In my case it is cut from a piece 3mm tufnol bonded, secured and filleted with epoxy and filler and carefully faired. The shape was worked out with cardboard templates passed over the rudder. It is only 25 mm. x 4mm. and goes right around the rudder about 150mm below and parallel to the water line, it looks just like a scale model of the fins you used to see around the the wings near the tip on some mid to late 20th century aircraft and works to increase the rudder power by reducing turbulence at the breakaway point just below the water surface. It was easy to do and cost very little though I am not sure how it would work on a shorter, less sophisticated foil.
If anyone is interested I might take the trouble to post a picture.
 
Lots of interesting replies, thank you.

Just to clarify further: Yes I had too much sail up, but only for 5 minutes, it had been correct for the past 5 hours! My main concern was to try to retain control of the boat and avoid collisions with the (very inconvenient!) traffic to windward. Kicker was already off, traveller already dropped down (although there is a case for raising it with the kicker fully off, counter-intuitive though that may sound). Can't bear away any deeper in the gusts as a) I'm already very deep and b) I can't steer! The two most useful suggestions so far I think are scandalising the main with the topping lift and reattaching the flow on the rudder. I didn't think of the first, and although I'm aware of the second, in the heat of the moment I may have grabbed too big of an armful! Boat speed incidentally wasn't that high, about 6 knots-ish, it was just directional control that was the issue. I think lack of boat manners may be the most accurate diagnosis, painful though it is to say!
 
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As the problem is I'm in danger of broaching uncontrollably into oncoming traffic, it's difficult to see how poling out the genoa could possibly help, even assuming I could leave the cockpit, and had time to unclip the pole, rig all the control lines and attach it!! I suppose it would get things over quickly...
 
maxmonk said:
As the problem is I'm in danger of broaching uncontrollably into oncoming traffic, it's difficult to see how poling out the genoa could possibly help, even assuming I could leave the cockpit, and had time to unclip the pole, rig all the control lines and attach it!! I suppose it would get things over quickly...
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Gybe away from the traffic, heave too and get a reef in while they go past.
 
I'm still thinkinking the issue is not the main but the genoa where the genoa creates the heeling motion and puts the bow down. In an emergency I'd let the jib sheets fly first before worrying about the main. What the state is the genoa (ie how baggy is it) and how tight was the genoa halyard?
 
My habit in such a situation is to first furl the genoa fully, it removes one problem child. Then cautiously gybe, start the engine and turn to windward. Then bring in the main. Turn down wind again and roll out some genoa. Mine is a motor-sailor, I not ashamed to get the motor putting some flow over the rudder so that the autohelm can maintain control while I struggle with the main.
 
I think DJE hits the jackpot with a blinding flash of common sense that is actually the obvious solution, hitherto overlooked!
 
fantasia7628 said:
Hoist the spinnaker to balance the rig (and go faster).
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The problem is that can cause its own problems particularly single handed :ambivalence:. Presently SWMBO will not let me play this game single handed :(, but the great thing with being single handed is she cannot see :D.

flaming said:
Sorry, but that is a bad idea... Works in theory, but not in practice as if you wander off your downwind course a little bit you'll get spun much quicker.

So the OP is basically asking how to stop broaching in a middle of the road modern boat that is a little overpowered.

Tip 1. KICKER. How many cruisers (or even many racers) touch their kicker after hoisting? It's a very important sail control with the wind aft of the beam. Broadly speaking it should be eased from the upwind setting but still about half on. Then if you start to broach dump it all the way. You'll be surprised at how effective that is.

Tip 2. Active driving. Keep an eye over your shoulder and bear away a bit when the gusts hit. If that takes you away from your course compensate by coming up above your course in the lulls.

Tip 3. Reattach the flow. Rudders work in two modes - with flow over them and when stalled. Actually I'll rephrase that. Rudders don't work when stalled... If you're heaving on the tiller and all you're getting is a lot of "breaking wave" noise from the rudder then your rudder has stalled, and turning the way you want to is not going to happen any time soon. Quickly push it back straight and then reapply the helm progressively. Think of this a bit like braking in a non ABS car.
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I would say information flaming:
I have found
1) Top batten parallel with boom is about right maybe slightly open..
2) Also cruising not racing do not let the situation develop if you can keep clear of the boats whilst you still have control, remembering that if a gust comes your going to loose it.
3) It does work but then I normally go for the gentle round up witht he stall if I have space. Once its happened a couple of times you find you can go straight from the round up to reefing the main...

I would not go for scandalizing the main, I would not have time plus I have no topping lift. Also if I had time to see the gust coming I have time to bear away to broad reach, where I can just go deeper and faster until the gust has gone. If there is a wave or 2 around it can be time to practice your surfing :D

maxmonk said:
I think lack of boat manners may be the most accurate diagnosis, painful though it is to say!
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Did you dip the boom in the water? that always ads to the fun, the main starts coming in as you are trying to dump it :ambivalence:.

There are boats out there like this I know, then they make good challenging boats to sail. Some like to sail well mannered boats, some like a challenge. Just learn your boat her limitations, play silly buggers when there is no one (and nothing) about to hit. If not reef early and enjoy not spilling your tea staying in your cup. It can make for a great days sail, you just may spill your tea and stand in the odd pasty those events still make me and SWMBO laugh...
 
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If you are already dead running, with the head sail blanketed by the main, main fully eased, kicker fully eased, in a constrained channel, with threatening traffic, and finding you are at the limit of control, while shorthanded: You have failed. You are not now looking for tips about control, you are looking for a safe bail out. All part of lives rich tapestry. No boat that is fun to sail has a 'safe mode' downwind, with too much sail up aft. Next time, try to stack the deck more in your favour. Reef early to avoid disappointment. Practice reefing, both sails, in any wind angle, at any wind strength. Look further ahead for threats.
 
onesea said:
The problem is that can cause its own problems particularly single handed :ambivalence:. Presently SWMBO will not let me play this game single handed :(, but the great thing with being single handed is she cannot see :D.



I would say information flaming:
I have found
1) Top batten parallel with boom is about right maybe slightly open..
2) Also cruising not racing do not let the situation develop if you can keep clear of the boats whilst you still have control, remembering that if a gust comes your going to loose it.
3) It does work but then I normally go for the gentle round up witht he stall if I have space. Once its happened a couple of times you find you can go straight from the round up to reefing the main...
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I'd go more open, but I'm not going to quibble. Agree don't let the situation develop, but worth while knowing a few tips to get out of it because sometimes they do develop...

Picking up on the extra information that the OP gave, he's saying he couldn't bear away any further.

This prompts the follow up question - was these round ups progressive, with time to react and puts lots of helm on, only that wasn't enough, or were they "snap" roundups happening very quickly and leaving you thinking "what happened there?"?

If the latter the problem could actually be running too deep, and getting oscilating flow over the main, so instead of always going luff to leach, it could instead start going leach to luff, you react to that, then it reattaches luff to leach and the boat starts turning very suddenly.
 
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