Running with the wind

[Sixgun77]

I have one friend who tells me that running with the wind is the best way to go when possible, and another who tells me that running with the wind is the least efficient way to sail. Who is closest to correct?

I would think that running with the wind would be best because all your force is in the direction you are travelling, rather than relying on the keel to stop lateral movement.

 

[kloudie1]

In a typical sailboat, running downwind is slower because the wind speed across the sail is slower (windspeed minus boatspeed) so it is generating less driving force. This is a typical "Polar Diagram" and clearly shows that a typical sailboat slows down as it begins to point downwind.
http://www.liveskipper.com/wiki/doku.php?id=en:boats:polars

 

[Allan12210]

When running with the wind, the main is stalled. At that point of sail you rely on pushing the air in front of the sail (resistance to forward progress) out of the way. Increasing the curvature of the sail (draft) to slide the air off the edges of the sail just reduces surface area and thus reduced speed. Better to crack off to a broad reach to allow air to flow over the sail for more speed than extra distance traveled. You can verify this with a GPS. Set a waypoint directly downwind and look at the velocity made good (VMG) on the GPS, not speed over ground (SOG). VMG will increase as you sail slightly higher from dead downwind.

 

[Nodak7]

I have one friend who tells me that running with the wind is the best way to go when possible, and another who tells me that running with the wind is the least efficient way to sail. Who is closest to correct?

I would think that running with the wind would be best because all your force is in the direction you are travelling, rather than relying on the keel to stop lateral movement.

Six, the REAL power of a sail is not in the wind that it catches! It is in the lift you get as the wind passes over it (like an airplane wing). You cannot get that lift when going downwind since all you get is the "push" from the wind.

Example: If a sail is rigged correctly and set properly you can actually go faster than the wind speed. That cannot be done going downwind. Your friend is not correct in his statement.

 

[tomgrigsby]

Oh my - That's really uniformed information from your friend. Spend a few days on this website http://www.arvelgentry.com/ This is website courtesy of a post from RichH. Learn how your sails work, and you'll be a far better cruiser - why take 12 hours to get somewhere when you can do it in 10 or less, right?

 

[Stu Jackson]

It's a sailboat. It all depends...

The previous advice is all very good and explains the issues in multiple ways, all valid.

In our case, the last hour to 45 minutes is usually DDW. While it is certainly faster to gybe downwind to get the benefits of the polars and sails, it is basically a "What a PITA to gybe every five minutes" routine 'cuz the fairway, while not narrow, is constrained by rip rap and containerships. Just a local issue on the Alameda Estuary.

I also love to hoot across the Bay from the Golden Gate Bridge to Treasure Island sailing wing-on-wing with a BIG grin. Usually on starboard tack so I only have to gybe the jib when I turn to starboard to go home.

If you ever start to race your boat (and many of us have said "I never will," but tend to end up doing it anyway), DDW is really slower.

 

[Sixgun77]

Thanks everyone. I had read up on how the sails work as airfoils before I got my boat and understand the principle. I was told by 1 person that running with the wind worked really well if your main is let out to one side with the jib sheeted to the opposite side. I'm still learning all this, and no amount of research can replace experience. I have been out enough to know that I'm more comfortable watching the sail than I am watching the wind vane on top of the mast.

 

[Ray Bowles]

Running is the point of sail that required the least amount of work on the part of the crew. Just pole out the headsail and rig a preventer on the main. Now just steer.
So if you just want to lay back and listen to the music as you quietly get pushed homeward this is what you do. As you learn more about your boat you will get a chance to try other points of sail. I love to find sailing technical books to read during the winter so I have new ways of sailing to try each spring.
Enjoy your boat. Ray
PS. Please rig a preventer while you learn to run.

 

[YVRguy]

I agree with Stu. You might get a bit more boat speed on a broad reach than a run, but if where you want to go is directly downwind, the extra distance you travel on a reach might negate that - in addition to the PITA factor.

On the other hand, wing-on-wing can be a difficult point of sail to maintain, particularly with quartering seas or if the wind is changing direction slightly. Guess it depends on your situation and preference. Some people will go far out of their way just to find a point of sail that gives them a couple of extra knots.

 

[YVRguy]

One other thing.. Your friend may be confused between sailing and "surfing." Normally your boat's top speed is restricted by its hull design and the maximum theoretical speed that it can be pushed through the water while sailing. (That is called your "hull speed" and no doubt many of the members here can tell you how to calculate it.) The one time when you can push past this limit is when you are running downwind and the waves lift the hull partly out of the water and literally push you forward. This is called surfing. It's entirely possible that your friend had a fun downwind run where he was surfing well past his normal top speed and because of that he has concluded that directly downwind is the "fastest point of sail." In a way that would be correct but in truth you're not really "sailing" at that point.