Reefing upwind vs downwind??

[Airscrew]

As a sailor with some experience, but as a new (and first) owner of a Centaur (bilge keel), I am struggling to get my head around this.
I have read around this a bit, and seen a number of comments along the lines of, "it depends on the boat, the conditions, and the point of sail."
But I might get lucky and get responses from people with similar configurations and experiences.

Scenario.
Saturday just gone, in the Solent, wind 20ish gusting 25ish (someone at the club later claimed they saw 30). Fine reach to close hauled. Sea slight.
Last summer we tried some experimentation in varying conditions, trying to avoid excessive weather helm
Based on that, we set off on Saturday with 2 reefs (slab single line) in the main and full genoa (approx. only 120% I think - it came with the boat). Simple cruising Dacron but both v.good condition (for cruising.)
But Bingo.
For the first time the boat is quick (for a Centaur!) and truly balanced. Sails nicely trimmed for the conditions (although I say it myself!). Fingertip stuff, in the groove all the way. Ease the main the gusts. Tracking on rails. 6kts+. Big smiles.

Sunday the Met conditions were very similar, but the experience very different.
20/25kts. Broad reach most of the way, around 120'. 2 reefs and full genoa.
Initially very good, but as the swell increased a little, we needed to ease the main more, but still needed alot of tiller to go over a swell (coming with the wind from stern/quarter) to counter the tendency to round up. With all the negatives of drag, leeway, speed etcetc.
As we got into a large swell AND a gust, I needed to ease the main massively, until all-out, and yet we still needed full rudder until the swell passed by.
We were at the limit. Fast, but hard work and inefficient.
It didn't get any worse, and we didn't round up, but here are the questions.

1.
Would the next step have been to fully drop the main (no we don't have a 3rd (yet))? And proceed genoa only.

2.
Or better to roll away some genoa as the next step.?
The question is because last year, experimenting with rolling a way some genoa (with or without main reefs) made the tendency to roundup worse.
I understand the principles of CLR and centre of drive, and with an overlapping genoa.

Should I have started (downwind) with the traveller already set to depower the top of the main. We have a peg in hole traveller, which is not realistically adjustable under load, unless you want to lose a finger or two).
(That would be traveller eased/away/to leeward to depower, yes??)

3.
Would you set-up (reefing) differently for upwind vs downwind (for cruising not racing).
Why?

I would be very happy to get a blend of personal experience responses, and some physics/science responses

Thanks in advance.
Jonathan.

(NB. We don't have an adjustable backstay on a Centaur)

 

[jwilson]

There are two factors affecting helm balance, centre of sail area and heel angle. Even if you have the sail area centred forward with full genoa and reefed main, if you heel past a certain amount the weather helm generated by heel will 'overpower' the sailplan balance. In these circumstances rolling away some of the genoa MAY help. If it doesn't then dropping the main should do so.

The other thing that may help on a broad reach is anticipating each roll-induced heel and bearing away just before it happens.

 

[Porthandbuoy]

Are you talking 20 to 25 kts apparent wind or true?

Fine reached to close-hauled at 6kts showing 20 kts apparent wind and there's a lot less true wind, so you were probably reefed correctly for the conditions

Broad reach, 120 as you say, and doing a similar speed, yet still showing 20/25 kts you were most likely overcanvassed as the true wind may well have been around 30kts, or more in the gusts.

 

[lw395]

Full genoa in over 20knots true may be your problem.
On a broader reach, a lot of your genoa will be oversheeted to stop the top from luffing or flogging.

What you're not telling us is how much the boat was heeling.
If you can roll away a bit of genoa and optimally move the sheeting forwards and/or outboard to get the whole sail working together, balance may have been restored.

If you are racing and the boat feels underpowered 10% of the time, you've got too little sail up.
If you are not racing and it doesn't, you would probably be happy with less sail up!

The whole point of a roller genny is that it's easy to reduce sail and see what happens.
If you are going to push keeping full genoa up, then I think you need to be easing it in the gusts and/or steering to keep it working well, not just fighting it with the tiller.

 

[alahol2]

"As we got into a large swell AND a gust, I needed to ease the main massively, until all-out, and yet we still needed full rudder until the swell passed by."

If I am broad reaching the main would be virtually fully out all the time. I wouldn't be able to ease 'massively'.
I would suspect you were oversheeting both main and genoa. Following waves can cause havoc, getting them right is just a matter of practice.
I was out the same days going Portsmouth to Newtown and back. Saturday single reefed main and 1/3 or 1/2 genoa, overpowered at times but generally OK. Single reef and full genoa on Sunday very comfortable and fast ride home.

 

[johnalison]

I agree with the over-sheeting theory, which would certainly make the boat hard to handle. I would always prefer to have a reasonably balanced sailplan. In the first place, this will set you up for changes in course and wind strength. Secondly, either sail when full will put larger loads on sheets and equipment and be much harder to furl, take in or reef if needed.

 

[Iliade]

I bought a smaller genoa last year as the monster I had previously would cause weather helm with the main down!

The Centaur seems to work best with a big main rather than a big foresail but downwind, if the foresail is big, it is definitely better without a shadow!

 

[William_H]

As said weather helm or rounding up is often more a function of the heel angle. That is the drag of the hull and keel is not under the drive of the sails. Now even a boat sailed relatively flat will get an angle of heel on the side of a beam sea. So you will get this round up tendency. There is not much you can do about it. This aspect of course is exacerbated by being over powered. In my little boat with hank on jibs I would always reduce jib size first because of the ease of dumping the main sail pressure while maintaining tight sheeting on the jib. (when beating). I then reef if it is still overpowered because main is eased so much it is flapping more than driving. My little boat is more heeled and overpowered on a reach than when beating but on a reach speed is not so much dependant on sail set as beating. So I often just ease the main and jib to resist too much heel on a short reaching leg. ie sail configuration is always about optimum for beating. olewill

 

[wooslehunter]

I was out in the Solent Sat & Sun in a Centaur too: upwind on Sat Chi - Lymington & downwind on Sun to go back.

IMO, you're doing great upwind. I've never managed to get the performance as good in F4-5. I also had two reefs in the main although a small gennoa reef. That said, my gennoa is 130% (at the advice of the sailmaker) and seems to be a little too big for up wind. Your 120% sounds about right. So, the setup was very similar. I generally roll a little away upwind before being over powered as this allows higher pointing & better speed. Upwind boat speed was 4.5 - 5kts at 45 degrees apparent & perhaps going up to 35-40 degrees in the gusts. So up wind as the wind increases, I'll first take in a little of the gennoa before being over powered. I'll then take a main first reef, followed by a second. Only if I'm further over-powered will I start taking in more gennoa. I do have a third reef on the main which is not normally rigged. If it looks as though I'll need the third, I do one of two things: re-rig the lines first to second & second to third, or more commonly go to the pub instead.

Downwind on Sun though I had no reefs. True wind speed peaked at slight below that of Sat but not much. I needed to sail between 120 & 180 off the wind. At those angles, the main was fully out all the time. Everything was reasonably under control although as the swell increased across Hayling Bay, I did have to steer quite actively to avoid large course changes due to the boat rolling. It does sound as though you were over-sheeted & this is where leach tell-tales work well. I can get mine flying nicely at 120 off the wind. Over sheeting causes them to curl backwards. Downwind & over sheeted, the boat doesn't have any weather helm. But, if it does come up beyond, 150 - 120, the main starts to power up, the boat rolls further & it can if not controlled, become almost uncontrollable screwing up into wind.

As I get to 150 off the wind, I'll consider bringing the gennoa over to the windward side & very importantly, polling it out. Polling out gives me an extra knot and stabilizes the sail. I can sail like that from 150 until 200 (i.e. 20 by the lee). These are limits though and at 150 I do have to be careful not to back wind the gennoa. At 200 I have to be careful not to accidentally gybe. But from 160 to 190, things are quite stable.

 

[Airscrew]

Thanks to you all for taking the time to reply. You raise some very good points, which are all taken onboard.

Downwind we had relatively little heel. But ofcourse the light swell would lift and push the stern first, then create some heel, and I understand how this 'moment' changes the balance of CLR and CD, out and then round.

Bearing away in advance of a larger swell will be practiced more

I now see we were oversheeted on both genoa and main. Lesson learned.

Also, almost every boat and sail combo is different, so I will continue to experiment and learn as needed.

And I can now answer my own question, as I don't have a 3rd reef. If the situation had worsened, drop the main and downwind with genoa alone.

 

[KellysEye]

>Initially very good, but as the swell increased a little, we needed to ease the main more, but still needed alot of tiller to go over a swell (coming with the wind from stern/quarter) to counter the tendency to round up. With all the negatives of drag, leeway, speed etcetc.

I think you have answered your question you should have eased the main over more. The key to fast sailing is always keep the boat balanced with no lee or weather helm which is needed if you have a wind vane.

 

[Neil_Y]

Pretty much any boat with swell on the aft quarter will be pushed into a roll where she heads up, my reaction would be to bear away as the stern starts to lift before the load comes on the rudder. She'll head up even if you are motoring fast which shows the sail plan probably has less effect than you think its more hull shape and speed on this point of sail.