How to avoid rounding up whilst sailing downwind

M

maxmonk

New Member
Joined
21 Jul 2008
Messages
16
Visit site
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?
 
Not sure there's a cure - I think it's more about hull shape and rudder depth. However, flattening off the main (halyard, outhaul, cunningham, backstay all on hard) might help by taking some power out of it. Oversheet the genny, to keep some pressure ahead of the CLR?
 
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?
Click to expand...

The answer will depend on crew size, boat size, sail plan, purpose of the passage.

Assuming single handing or a small crew of two with autopilot and cruising I would not leave a full main downwind if I see it gusting above 18kts. Even with a preventer it can get fairly dangerous if on autopilot when a wave try to broach you. I would reef early or even centre a very small main just to control the rolling (I have in mast furling so I can make it as small as I want) and I would let the Genoa do his job and still get very near to hull speed. But this is on a 42ft yacht. Perhaps on smaller size yachts the main would be easier to tame.

But in my case I have a Genoa #1 (large) and in-mast furling. If you have only a small jib and large main then running under jib only will not give you the desired cruising speed.

Clearly racers would take whole different actions ...
 
Last edited:
GrahamM376 said:
I would be running on 135% genoa only. 38ft boat
Click to expand...
Me too. - on a 24 footer!

I wouldn't think a full genny would be noticeably slower than full white sails in 15 kts apparent downwind (must be 20 true) - and a lot easier to manage if the wind builds or goes gusty. In clear water I'd pole it out, if it's a bit crowded, so I'm likely to have to dodge at short notice, I'd adjust my course if necessary to keep it full .
 
Sell it and buy something with decent manners! Not entirely facetious - that's what my mate did and now has a gorgeous Starlight 35 that behaves like a yacht.
Another friend sailed on this 305 in the SIPR, solo-helming on a reach from Salen to Craighouse and it took over 6 months for his elbow to recover. I have heard tales of rudder fairing and adding a notch at the tip to stop it stalling but not a quick fix.
 
Yes I agree with all comments about running under genoa only - that's what I would normally do if planning to run downwind. On this occasion though, the wind had gradually come around from a beam reach so I'd gradually eased the sails out as it became a broad reach. It had been nice and steady too, not gusty at all.

Obviously like all things the situation is better avoided in the first place, but my question was really, having inadvertently ended up in the situation, how best to manage it?
 
In the gusts head more downwind.

Not convinced kicker off will help - it is as much a function of the shape of the boat that is in the water as it is the sail plan - ie more heel and the worse it gets. Try reefing whilst whilst heading downwind (so long as whatever self steering will cope) - it may work.
 
My opinion - for what it is worth.

If the rounding up is due to the centre of effort being to one side of the boat, then you could try hauling the mainsail in. This would bring the force created by the main round to the side, making the boat heel, rather than twist round.

However, it is much more likely that the rounding up is caused by the boat heeling, giving large amounts of weather heel. The above suggestion would make things worse.

I don't know that you can do anything, except reef earlier, or watch for the gusts and bear away before they hit, being careful not to gybe. This would bring the force from the sails more in line with the direction of travel, thus heeling less.
 
maxmonk said:
Yes I agree with all comments about running under genoa only - ...............Obviously like all things the situation is better avoided in the first place, but my question was really, having inadvertently ended up in the situation, how best to manage it?
Click to expand...

I would go along with hoisting the boom, turn into wind and drop it, if necessary with engine and autohelm assistance if shorthanded.
 
Mmm. Exactly the situation I was contemplating for tomorrow, I am glad the forecast has come down a bit.

As others have said, the solution is to reef early but it is not an easy choice if you are racing or if the wind is up and down. I would get some canvas off, by the easiest means, and take the genoa right in or furl it. With luck you will fall behind the windward traffic and you can then deal with the main. Leaving out a bit of genoa might give you the option of coming right round and hove too, for a bit of a breather. I have a tiny main so would have the option to run off and gybe but I would be wary off this with a larger sail.
 
maxmonk said:
Yes I agree with all comments about running under genoa only - that's what I would normally do if planning to run downwind. On this occasion though, the wind had gradually come around from a beam reach so I'd gradually eased the sails out as it became a broad reach. It had been nice and steady too, not gusty at all.

Obviously like all things the situation is better avoided in the first place, but my question was really, having inadvertently ended up in the situation, how best to manage it?
Click to expand...

The easiest way is to keep on course and sheet in the main until it is hard in. That will kill the power.

The longer term answer is to sell the boat and get a proper sailing boat!
 
I would haul down on the vang to flatten the main and stop the boom lifting. You may need to attach the vang at the rail to properly pull down on the boom. Then gybe the headsail so it's blanketed by the main and drop/furl it. Then haul in the main as you turn onto the wind. Apparant wind will increase by your boat speed so be ready for that. Drop or reef main, turn back onto course.
 
mainsail1 said:
The easiest way is to keep on course and sheet in the main until it is hard in. That will kill the power.
Click to expand...

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.
 
You must log in or register to reply here.

Share this page

Top