Beating to windward using just the Genoa...

[stevie69p]

Ok first off to all ye old salts who have no doubt done this, but today was my first time out single handing since buying new (to me) boat (MG Spring), and after initially motoring out of the marina and down the river channel I thought happy days, it's going to be a nice beam / broad reach to Holy Loch... which it was. Relaxing, lazy sailing in winds of 15 to 20 knots.

So on reaching Holy Loch, I sailed up towards the head of the loch and tacked round thinking I would harden up with the Genoa, and hoist the main. Well harden up indeed I did, and the boat felt fine, helm felt neutral, even a wee tiny touch of weather helm... stuck on the autohelm and it coped fine too. I thought to myself " well this is quite nice, I'm doing 4.5 to 5 knots SOG and only 10 degrees of heel" rather than the usual 25 degrees... Sailed the whole way back just as an experiment; reckon she was tacking through 100 degrees. Literally walked away from a Hunter Pilot 27 who were struggling with reefed main and Genoa...

Now... we recently tried Genoa only in similar winds on a weeks cruise, but she wouldn't point, but I now reckon that was because we had a couple of rolls furled away, and what's needed is that big, sweeping overlap to provide power slightly aft of the mast, and b) a decent sail shape.

Thoughts from others appreciated!

 

[forelle541]

On my Sadler 29 I'm amazed at the way she will sail on all points with just the Genoa, makes us quite lazy.

 

[johnalison]

It can be quite comfortable to sail with genoa or even a working jib, but it won't be as fast, especially in terms of VMG to windward as sailing with a balanced sailplan, which is why you will never see anyone race in this mode.

 

[Javelin]

Kind of depends on the rig design but in general the older boats, certainly from the IOR period will be happy under jib.
Less so with the modern big main rigs.

My 1985 boat reaches around 80 to 85% of its upwind vmg from 6knts wind to 18knts with just the genoa and as a result we spend a lot of relaxed cruising days with the main snug in its cover.

 

[William_H]

Yes it is quite likely that the jib partly furled will not point as well as the whole jib. This may be because you did not or can not sheet in tight or may be that you did not move the sheeting car to correct position or it may be that the roll of sail messes up the air flow. (or a combination of all of these) sorry I am no expert as I would not have a furler on my fractional rig boat as I like to race it to it's best potential up wind. olewill

 

[stevie69p]

Well I have to admit I'm not really out to be a racer (Wednesday nights on dinghies take care of that!), and very much still a bit of a novice on the bigger boats. I just had it in my head that it would sail like a dog in anything much past a beam reach under headsail only.

With full rig up, this boat needs reefing at 15knots. It's got a fairly big rig for the size of boat, and it just feels like this might give a decent 'don't scare yer grannie' sail plan for when you don't want to be halfway up in the air LOL... Great fun with full rig and a crew mind you. What I did find was that I had to allow her to build up speed from a close reach after tacking, and gradually point up from there.

 

[jwilson]

On most masthead or near-masthead rigs full genoa only is actually a pretty efficient sail as long as you have sheets/cars right, and only two strings..... The sail is inherently more efficient area for area than most mains as there isn't a big lump of mast upsetting the airflow over the luff.

If there's enough wind to heel you the "theoretical" unbalanced lee-helm sailplan is largely cancelled out by the weather helm generated by heel.

 

[reeac]

I accept that we are talking about beating to windward but I have a comment about running with genoa only. I tried this once at sea under wind over tide conditions and the sail and rigging snatched badly and I soon gave up. I think that a mainsail avoids this by being attached to the mast and boom along two of its three sides.

 

[Daydream believer]

I do not know if you have tried this but on my Stella I had a very weak Stuart Turner 4hp inboard that in a chop would only push the boat at 2kts
Likewise the genoa on its own might do 2kts & not point particularly high .
But for some reason if I motor sailed with engine & genoa together the resulting speed was greater than the sum of the two & I could get 5+ kts of boat speed & point fairly high
I demonstrated this to the owner of a half tonner on an EAORA race when we ripped the main. The owner intended to turn back instead of heading to our destination which was our home port as the genoa alone would not do the job. But starting the engine ( which would not get us home on its own either) made an enormous difference & we easily made home

 

[Poignard]

I accept that we are talking about beating to windward but I have a comment about running with genoa only. I tried this once at sea under wind over tide conditions and the sail and rigging snatched badly and I soon gave up. I think that a mainsail avoids this by being attached to the mast and boom along two of its three sides.

If I can't be bothered to pole out the genoa when running downwind, I prefer to just have the main set rather than have the genoa filling and collapsing as the boat rolls.

 

[LONG_KEELER]

I do not know if you have tried this but on my Stella I had a very weak Stuart Turner 4hp inboard that in a chop would only push the boat at 2kts
Likewise the genoa on its own might do 2kts & not point particularly high .
But for some reason if I motor sailed with engine & genoa together the resulting speed was greater than the sum of the two & I could get 5+ kts of boat speed & point fairly high
I demonstrated this to the owner of a half tonner on an EAORA race when we ripped the main. The owner intended to turn back instead of heading to our destination which was our home port as the genoa alone would not do the job. But starting the engine ( which would not get us home on its own either) made an enormous difference & we easily made home

Yup ! Works well doesn't it.

 

[jac]

Another factor to consider is sail shape.

Whilst a well balanced set of trimmed sails will usually outperform the same sail area in a single sail due to factors such as the slot and reduced weather ( or lee) helm, it does depend on the sails being a good shape.

With full sails ( or a smaller Jib set unfurled) that is not a problem.

However with furling jibs, it doesn't take many rolls to end up with an inefficient jib shape , hampered by the fact that you have a massive roll of material down the leading edge of the jib further messing around with the aero dynamics. So keeping full main and furled jib ( which is the traditional first reef for many) may be less effective than retaining full jib and just ditching the main as the Jib then continues to operate as efficiently as ever.

 

[johnalison]

Another factor to consider is sail shape.

Whilst a well balanced set of trimmed sails will usually outperform the same sail area in a single sail due to factors such as the slot and reduced weather ( or lee) helm, it does depend on the sails being a good shape.

With full sails ( or a smaller Jib set unfurled) that is not a problem.

However with furling jibs, it doesn't take many rolls to end up with an inefficient jib shape , hampered by the fact that you have a massive roll of material down the leading edge of the jib further messing around with the aero dynamics. So keeping full main and furled jib ( which is the traditional first reef for many) may be less effective than retaining full jib and just ditching the main as the Jib then continues to operate as efficiently as ever.

For most of us, that is not always going to be the better option. In the first place, a modern jib, laminate or similar, with a padded luff will retain most of its performance even with four or five rolls or even more. Secondly, sailing with full genoa means that one is handling a large sail in higher wind speeds with the resulting greater forces on sheets and making it harder to handle, as well as making the furling much harder with no main to put it behind.

 

[jac]

For most of us, that is not always going to be the better option. In the first place, a modern jib, laminate or similar, with a padded luff will retain most of its performance even with four or five rolls or even more. Secondly, sailing with full genoa means that one is handling a large sail in higher wind speeds with the resulting greater forces on sheets and making it harder to handle, as well as making the furling much harder with no main to put it behind.

Indeed - depends on the type of sail and agree that a modern, non stretched sail with padding to retain shape is great but how many baggy old Gennys do you see with maybe 8-10 rolls in them.

For next boat I might be inclined to move towards something with a higher cut ( more yankee or blade jib in shape) and padded luff and use that as primary foresail knowing that each roll provides a useful reduction in sail area. Can always then get a larger, possibly lighter weight No1 that is never furled but instead is only used upwind in low wind speeds.

 

[STATUE]

Clearly there is no shame in using genoa only - I shall do it more often, but it wouldn't work for my most frequent engagement -"Hove to" for long lunches !

 

[AntarcticPilot]

My Moody 31 is perfectly happy under Genoa alone, and it's a much easier rig for a light crew to handle. As others have said, it won't be quite as weatherly as the full rig, but it's certainly a useful option.

 

[lw395]

I first found out exactly how well a big genoa will drive a boat up wind while racing.
We dumped the mainsheet to bear off to avoid a collision.
The boat would not bear off much at all until we dumped the genoa sheet.

But it only works that well once the boat has built up some pace.
From a standstill, the boat will only go downwind.
Other boats may vary!

 

[BrianH]

I accept that we are talking about beating to windward but I have a comment about running with genoa only. I tried this once at sea under wind over tide conditions and the sail and rigging snatched badly and I soon gave up. I think that a mainsail avoids this by being attached to the mast and boom along two of its three sides.

If I can't be bothered to pole out the genoa when running downwind, I prefer to just have the main set rather than have the genoa filling and collapsing as the boat rolls.

I appreciate those points with lighter winds but single-handed, as I usually am, with stronger winds I prefer to run under headsail alone - the drive forward of the mast just pulls like a train and steering is easier.

Below is of my Trapper 500 in 2004 running north up the Istrian coast at 7 knots with 30 knots (apparent) of sirocco. As I was starting to get some spray aboard I did close the hatch and put the washboards in soon after the photo.

 

[wotayottie]

Now... we recently tried Genoa only in similar winds on a weeks cruise, but she wouldn't point, but I now reckon that was because we had a couple of rolls furled away, and what's needed is that big, sweeping overlap to provide power slightly aft of the mast, and b) a decent sail shape.

Thoughts from others appreciated!

Likely you are right - the rolls round the furler will destroy the shape of the sail. In my boat when racing we reef all the way to the second reef in the main before even thinking about furling the genoa which is a pretty new cruising laminate with padded luff.

Power aft the mast! No - doesnt matter how the sail is furled, its power is transmtted in the same way through the forestay and the sheet winch