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Old 29-10-2024, 13:14   #16
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Re: Motoring with sail up???

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Originally Posted by SailingHarmonie View Post
When motoring in dead calm conditions, or straight into the true wind, having sails up does nothing good, and a whole lot that is detrimental. The sail is flogging in the apparent wind with a 0 AWA, it adds no stability, no significant roll damping, and it adds extra windage drag, so actually slows you down.

It is only done out of ignorance, or laziness.

Each boat has a different set up, but we see the first hints of help from sails when we are at least 27 degrees AWA. That's a lot better than we can sail, and it only works with the mainsail. With any AWA smaller than that, the main is furled.

Beg to disagree.


At 27 AWA if there is any wind at all we can even sail without the engine. Not optimal VMG to windward but still some forward progress.



At 10 AWA motorsailing there is still a tiny bit of drive from the sail, and a lot of added stability. So very much worth having the sail up.



That is, provided you flatten the sail completely and put the traveler up all the way to windward, above the centerline. If you have baggy dacron sails, this won't work nearly as well.
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Old 29-10-2024, 13:28   #17
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Re: Motoring with sail up???

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Originally Posted by Mike OReilly View Post
A headsail won't provide much lateral resistance to rolling. A mainsail sheeted tightly to centre can.

...snip
Actually it does if done right. Set genoa with both sheets in the midship and furl in so it's tight. Much better than main sail, less wear and noise.
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Old 29-10-2024, 13:36   #18
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Re: Motoring with sail up???

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Originally Posted by SailingHarmonie View Post
...And as a matter of fact, the language of "standon" and "giveway" has been dropped from the rules, decades ago. Those words do not appear in the ColRegs. ...
Rule 16 in both COLREGS and US rules is literally "Rule 16 - Action by Give-way vessel" and Rule 17 is "Rule 17 - Action by Stand-on Vessel"


Quote:
Rule 16- Action by Give-way Vessel
Every vessel which is directed to keep out of the way of another vessel shall, so far as possible, take early and substantial action to keep well clear.

Rule 17- Action by Stand-on Vessel
(a)(i) Where one of two vessels is to keep out of the way, the other shall keep her course and speed.
(ii) The latter vessel may, however, take action to avoid collision by her maneuver alone, as soon as it becomes apparent to her that the vessel required to keep out of the way is not taking appropriate action in compliance with these Rules.

(b) When, from any cause, the vessel required to keep her course and speed finds herself so close that collision cannot be avoided by the action of the give-way vessel alone, she shall take such action as will best aid to avoid collision.

(c) A power-driven vessel which takes action in a crossing situation in accordance with Rule 17(a)(ii) to avoid collision with another power-driven vessel shall, if the circumstances of the case admit, not alter course to port for a vessel on her own port side.

(d) This Rule does not relieve the give-way vessel of her obligation to keep out of the way.
Technically I suppose you are right, since the rules use a hyphen between the words
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Old 29-10-2024, 14:47   #19
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Re: Motoring with sail up???

For me, the wind usually comes up after a few hours.

Also, since I know the direction where it will be coming from and is going to be beneficial to my motoring, I'll put the mainsail up before leaving anchor.

Also for getting home, I can sail much closer to the wind by motor sailing with mainsail up only.

Other times, I use the engine to get around obstacles like a group anchored oil tankers then go back to sailing.



getting around tankers.

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Old 30-10-2024, 11:54   #20
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Re: Motoring with sail up???

A mainsail sheeted hard amidships DEFINITELY reduces rolling. It acts in the air like a flopper-stopper acts in the water. When the boat rolls, the sail must be swept through the air sideways. There's a lot of resistance there and the boat doesn't roll nearly as far.

Many commercial fishboats around here had permanently installed trisails on their masts to stabilize them when traveling fast - when their in-the-water towed stabilizers would trail behind and impart more drag than roll resistance.
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Old 30-10-2024, 21:02   #21
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Re: Motoring with sail up???

Makes your engine work harder from the sails drag in the air.
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Old 30-10-2024, 22:08   #22
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Re: Motoring with sail up???

I get better fuel economy with the sail up because if there is even a breath of wind the sail is not flogging and apparently offers a little drive. But even if it cost me a little more gas, the comfort is worth it. I am not in the Salish Sea though. Where I am there is typically some kind of swell and usually at least a breath of air. If it is really flogging then I'll take it down, but that is pretty rare.
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Old 30-10-2024, 22:29   #23
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Re: Motoring with sail up???

I motor with my main up to be easily visible to other traffic.
And as mentioned earlier, sailing shorthanded one less thing to do when the wind comes up.
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Old 31-10-2024, 02:43   #24
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Re: Motoring with sail up???

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Originally Posted by boatpoker View Post
So they can perpetually claim "right of way"
You're supposed to fly the inverted cone day mark to show that you're a motor vessel for colregs purposes. I know, very few vessels do. Compliance on this rule is probably even worse than with the anchor day mark.

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Old 31-10-2024, 05:24   #25
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Re: Motoring with sail up???

Nice to see someone in compliance.



Strangely, in Canada certain vessels are exempt from using the motorsailing day shape, if they so choose:


Sailing Vessels Underway and Vessels Under Oars — Canadian Modification

  • (f)
    Notwithstanding paragraph (e), in the Canadian waters of a roadstead, harbour, river, lake or inland waterway, a vessel of less than 12 metres in length proceeding under sail when also being propelled by machinery is not required to exhibit a conical shape, apex downwards, but may do so.


However, I can attest that, at least in my local sailing area, I don't recall ever seeing a sailing vessel display the shape even if it was greater than 12m.
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Old 31-10-2024, 08:55   #26
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Re: Motoring with sail up???

What seems a dead calm to a power boater may still be useful wind for a sailor (with some help from the motor ...)


Often sailors will start the donkey and go for a time, hoping for the wind to fill in again. At times it does. And dousing / hoisting a sail - esp the main when it is not in-mast - is an effort. At times quite some effort.



Hence.



b.
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Old 31-10-2024, 09:40   #27
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Re: Motoring with sail up???

Maybe they have sails up for shade!

One day is one day, somebody will market a cat that has sail and PROPER POWER mated to proper prop and a high enough boom to have a nice cockpit out of the sun.

We boat mostly Seychelles. It is hot and 90% of the time we see the sail yachts, they are under power, as the tourists like the good season which is low wind.

My power comment is from this: Circa 350nm out and back ten day trip to outer islands.
One trip was a 55’ sailing cat.
The other trip was a 51’ powercat.
Guess which vessel used 50% more fuel than the other…

Sure, if we were stupid doing 25 knots in powercat we would have sucked lots of fuel, but for the 125nm crossing we sit at around 7-8 knots as we anyway have an overnighter and when there is some light we are after the Tuna.

If that 55’ sailing cat just had say two 200Hp motors, it would have matched the powercat fuel consumption. Instead it has puny motors that suck far more fuel at 7 knots than our twin 380’s.

I’d love the yacht I described as I do like sailing.
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Old 31-10-2024, 10:01   #28
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Re: Motoring with sail up???

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Originally Posted by Johan Leopard51 View Post
If that 55’ sailing cat just had say two 200Hp motors, it would have matched the powercat fuel consumption. Instead it has puny motors that suck far more fuel at 7 knots than our twin 380’s.
The sail cat wouldn't need bigger engines to be efficient, it would just need a more efficient drive system behind the engines. Engines are typically less efficient under light loads than heavier ones, so bigger engines would actually carry a slight efficiency penalty at low speeds where the extra power isn't needed.

The props and related hardware on a sailboat are typically compromised to reduce drag under sail at the expense of lower efficiency under power. The rudders are also oversized for use under power (which adds more drag), but there's nothing you can do about that if you still want to be able to sail.

Differences in hull shapes, weight, etc. can also be a big factor in why seemingly similar boats burn a different amount of fuel. Depending on the hull shapes, a sailing cat may experience a steeper drag rise when motoring close to hull speed than a power cat that's meant to exceed hull speed under power. So going from 7 kts to 9 kts on the sail cat may carry a bigger fuel burn penalty. But chances, are if you go slow enough, the sail cat will burn less fuel while motoring unless the prop configuration is particularly bad.
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Old 31-10-2024, 11:05   #29
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Re: Motoring with sail up???

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Originally Posted by NorthCoastJoe View Post
Makes your engine work harder from the sails drag in the air.
I've noticed this with winds under 3 knots (I have a roller furling main and go faster without the sail out) and with steady wind at 4 or 5 I sail. ��
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Old 31-10-2024, 11:33   #30
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Re: Motoring with sail up???

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Originally Posted by NorthCoastJoe View Post
Makes your engine work harder from the sails drag in the air.

Not if you do it right.
Doing it right means making the sail completely flat with the vang and outhaul on hard, putting the traveler up to windward of the centerline, and having at least 10 degrees of apparent wind.
Motor and sail work synergistically because of apparent wind generated by the boat's motion.
You can get a surprising amount of drive out of the sail in just a tiny breath of wind.
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