Sailing without the main.

[Fiddlesticks]

Hi all,

I've been watching a few YouTube sailing videos where the response to strong winds has been to drop the mainsail altogether and just use the headsail.

Meanwhile I'm reading about the theory of sailing.. no experience yet... But I'm given to understand that this could lead to unbalanced sails and would create lee helm.

Do they only do this going straight downwind? If not, what's going on?

Thanks
An (interested) non-sailor.

[Chotu]

It works just fine and is an easier way to handle the situation if you have a standard, non-furling main but do have a furling headsail.

Balance doesn't get too far off in most downwind headings and depends on the individual boat as well as what headsail you're using.

If it's really blowing, a little rag or washcloth of headsail can move you along nicely and in full control.

[Flagman101]

Yes it can unbalance the boat.

[sailorboy1]

different boats sail different, in high wind even unbalanced sails move you along pretty good and sometimes you do it just to slow down

[Yellowtulip]

If you sail dead downwind in strong winds with the mainsail up, the risk of an accidental gybe is high. A gybe is when the mainsail and boom crash across the boat with very high force. The flailing boom can kill. So, many of us drop the mainsail in high winds and sail using just the foresail. This doesn't usually mean a loss of speed.
The question of sail balance doesn't apply in the same way when sailing downwind as on a reach or beat. When on a reach, say, the centres of effort of the two sails must be disposed about the centre of lateral resistance so that the boat tracks in a straight line without too much effort on the wheel or tiller (some weather helm is desirable). When sailing dead downwind with just a headsail, the centre of effort is well forward, so pulls the boat along quite well. However the centre of effort will be slightly outboard inducing roll, which can sometimes be very severe. Some people like to use twin headsails for downwind sailing, to reduce or eliminate rolling. This is another form of sail balancing.

[Mike OReilly]

On my boat I’m more often sailing with mainsail only vs headsail only. The size and location of my cutter’s main makes this a better choice for balance and control.

I have gone with headsail-only when the convenience or safety of being able to roll in the sail quickly mattered, usually when I’m coming into close quarters with other boats or bumpy bits, but otherwise it’s not a good idea for my boat.

I think the reason most sail with headsail only is exactly this; the convenience of the furler. On most boats it will produce balance problems, but this can be outweighed by other factors.

[Breaking Waves]

Accurate answer “it depends”

Our fractional sloop, with good sails (good shape, low stretch), sailed very nicely and balanced right up to a very close reach on #3 jib alone. She would also sail well under reefed (we are talking windy conditions) mainsail alone.

Quite a bit of ‘balance problems” come from hull shape and heel - sail a sweet hull, sail it flatish, (and with well shaped sails, not stretched out) and usually your balance problems will go away.

[billknny]

As already answered, the answer is...(like all things sailing).. it depends...on the boat, the point of sail, and the skill of the skipper at sail trim.

When we are talking about "balance" of a boat we are talking about the ability to sail with a neutral rudder. A very well balanced boat will even hold a course that is self correcting, i.e., it will hold a stable course only with hydrodynamic forces without any change in rudder angle. Not every boat can do this, and very few can do it if they are not close hauled. I once sailed 600 miles without any kind of autopilot, the wheel just tied off, and trimming the mizzen sail to adjust course.


The balance between the area of the main and the area of the jib is PART of the balance of the boat, and this answer makes all the sailing text books because it is easy to explain. In fact, balance is a much more complex issue involving angle of heel, rake of the mast, hull shape, fore/aft trim, condition of the sails, sail trim, etc...

Just by way of example, the wind picks up and weather helm becomes too large, Skipper changes from a large jib to a smaller one. That actually moves the center of effort of the jib FORWARD and by the simplistic explanation the OP was given should INCREASE weather helm, but it does exactly the opposite...

I used to sail J-105's as a day sailed charter skipper in strong winds. for those boats the opposite approach was best: put the jib away and sail on main alone.

I sail a ketch, so I can drop the main, and with minor tweaks to the trim of the mizzen sail I can balance the boat to hands off steering on any point of sail above a beam reach.

On the other hand... many cruising sailors who sail with an electric autopilot ignore the issue of balance until it overwhelms their AP, and don't understand the loses of speed and control this causes. Never assumes that other boat knows more than you do. Remember: half of everybody out there is below average.

[HeinSdL]

Originally Posted by Breaking Waves

Accurate answer “it depends”

Our fractional sloop, with good sails (good shape, low stretch), sailed very nicely and balanced right up to a very close reach on #3 jib alone. She would also sail well under reefed (we are talking windy conditions) mainsail alone.

Quite a bit of ‘balance problems” come from hull shape and heel - sail a sweet hull, sail it flatish, (and with well shaped sails, not stretched out) and usually your balance problems will go away.

Agree with this, it depends. We had quite a good result beating out of the English Channel on just the #4 into perhaps 35 knots of wind. A very nice sail, cut quite high to not catch any water coming over, pushing the boat nicely along. But on other boats the more favourable set up might be different.

[wingssail]

When there is too much sail area for the wind or your comfort and a reduction is needed dropping the mainsail accomplishes that however it does upset the balance of the boat. Sailing deep downwind angles makes that unbalance less noticeable or important. Coming up onto a reach or to windward it will be noticeable.

But more importantly taking off that much sail is like using a sledge hammer to kill a mouse; it is over kill.

I'd rather see a single or double reef put in the main and, if needed, a few rolls in the jib, until the sail area is correct for the conditions. That is proper sailing and if you watch the pro's, that is what they do, (also the guys who write the books).

We reduce the headsail area first. Then if more is needed we reef the main, usually skipping the first reef. If the conditions require more reduction WE DROP THE HEADSAIL and sail the boat with a deeply reefed mainsail alone. Yes this unbalances the rig, but with the small mainsail area being well forward the unbalance is not severe. It is just part of our DNA to keep the boat sailing it's best (which does not mean overpowered or unbalanced). Our rudder is powerful and effective and the boat is easily controllable even in very high winds while sailing with a mainsail alone.

Once when returning to the marina under power our motor quit just as we entered the breakwater. To have some control we set the jib, it was quickest. By then however we'd passed our fairway. We turned into the wind to go back but with no main the boat would not tack and we crashed into the rock breakwater. At slow speed we did little damage except to our pride but we learned that the boat sails better, in more control, with a main up. It was fine downwind, but on any other of sail, no way.

[wingssail]

Originally Posted by billknny

Just by way of example, the wind picks up and weather helm becomes too large, Skipper changes from a large jib to a smaller one. That actually moves the center of effort of the jib FORWARD and by the simplistic explanation the OP was given should INCREASE weather helm, but it does exactly the opposite...

No, OP said he was given to understand that no main would lead to lee helm. Reducing the headsail while keeping the main full would lead to more weather helm.

[BozSail]

I think it REALLY depends on the boat. I have an old (built in 1980) Endeavour 37 sloop, which I sail single-handed quite a bit. I'm getting kinda old too (73) and somewhat physically weaker, so I'm a bit of a lazy sailor sometimes. I leave the main sail tucked away in the stack pack, and just furl out the 140 jib - usually all the way, but sometimes furled in a bit if it's quite windy. My boat sails very nicely that way on basically all points of sail from close-hauled to dead downwind. And, should I encounter a sudden wind shift or a fast approaching squall, I can react very quickly without having to deal with two sails by myself. I usually just set the head sail, set the course, set the autopilot and relax - works good for me.

[Eder]

I don't ever sail without a bit of main up (so far lol). It helps to minimize the downwind watusi.

[Pizzazz]

I am with @BozSail. My boat 1984 Hunter 31 has a masthead rig and most of the drive comes from the headsail. With a 155 genoa I can sail pretty much all points of sail with the headsail, losing about a knot of speed.

If sailing close hauled, you need the main and the headsail to balance the boat, adjusting the sail area to the wind conditions. But if sailing casually, you can do just fine with the headsail alone and you do not lose much.

If you have a fractional rig, most of the power comes from the main and I believe then it is better to use the main for power and the headsail for balance.

At the end of the day, it is all about how much work you want to put into it. If going on a casual afternoon sail with a number of people on board, it may be safer not to deploy the main to avoid the boom swinging around and hurting inexperienced passengers. But if you want to make the most out of it, you need the main up.

SV Pizzazz

[Don C L]

I do it. Yes, there will be lee helm, but how much will depend on the boat. I only do it when reaching to running in winds over 20 kts or so. Since the conditions will be in higher winds and larger swells typically, we all have our harnesses/pfd on. The weather helm built in to the system when main is employed is, among other things, considered a measure of safety. If you exit boat unexpectedly the boat should round up, tack and then heave-to giving you a chance of catching back up with the boat. In reality I have my doubts, and in anything over 10 or 12 kts I really have my doubts. So helm is not an issue for me once reaching to running. Once broad reaching to running it is useful to pole out the jib. Sailing with kids for me it makes even more sense too from a safety standpoint. Sailing home on a broad reach a while back it was blowing 20 to 25 and my daughter was asleep in my lap seasick. I was going plenty fast with jib only and had no main to worry about.