Boat doesn't budge in light winds

[Bigjim]

I have a Columbia 10.7. It is a big heavy boat so I didn't think it would sail very well in light winds, but I think this is ridiculous.

We race on Wednesdays at my local club. It seems we have light winds every Wednesday. But the last couple of races we experienced the following and can't figure out how to fix it:

The wind was from the Northeast at less than 5 knots and we were trying to sail to the windward mark. On the Port tack we were making 2-3 knots about 45 degrees off the wind. But when we tack over the boat stops. We trim exactly the same way as on the port tack and we sit there, zero knots.

The telltales are all flying properly but we are not moving.

We try to fall off the wind a bit to get some way on but nothing happens.

We jibed back to the port tack and we start moving again 2-3 knots. Tack back and sit dead in the water.

Anybody have a reason or a solution to why we can sail on one tack but not the other?

[roverhi]

Was your speed measured by a knot meter or GPS?? If the latter you may have been fighting current on one tack. A knot meter/log will give you speed through the water which you want for sailing efficiently. You could actually be going backward over the bottom but sailing as efficiently as possible. You need to be aware of both to get to the mark in the most expeditious manner.

[Bond_vagabond]

That is pretty strange. I'm no sail trim guru, but here are a few things I can think to check.

If you are using some sort of wind angle gauge, it may be out of calibration?

Some sort of assymetrical ballasting, water tank that allows water to slosh outboard on one tack but not the other?

If your prop or outboard is not on the centerline, that can make a boat behave differently on each tack.

Some aspect of your sailing location that makes you approach the wave action at a different angle with each tack, even though they are symmetrical to the wind. Often near land the predominant wave action will be from a different heading than the wind. Light boats especially can behave very differently depending on their angle to the waves, light wind making it even more pronounced.

Some asymmetrical windage, that interrupts smooth air flow over the sails on one tack but not the other.

Good luck

[Cheechako]

Just hard to say. One thing though, in light air, crack off your heading before you tack gaining speed, then tack. It helps keep you moving.

[sailpower]

Originally Posted by roverhi

Was your speed measured by a knot meter or GPS?? If the latter you may have been fighting current on one tack. A knot meter/log will give you speed through the water which you want for sailing efficiently. You could actually be going backward over the bottom but sailing as efficiently as possible. You need to be aware of both to get to the mark in the most expeditious manner.

Great point.

A gps gives speed over the ground (because the speed is calculated based on position change and not actually measured) while a conventional knot meter gives speed through the water (measured via paddle wheel).

Two different things but both useful.

[Bigjim]

Originally Posted by roverhi

Was your speed measured by a knot meter or GPS?? If the latter you may have been fighting current on one tack. A knot meter/log will give you speed through the water which you want for sailing efficiently. You could actually be going backward over the bottom but sailing as efficiently as possible. You need to be aware of both to get to the mark in the most expeditious manner.

It's happened three times and the knot meter showed Zero. But it was also obvious we were not moving.

Once, we were trying to move against the waves, so we figured the waves were stalling us. But, the other time we were about 50 degree off the waves and making zero knots. On the other tack we were moving into the waves and doing 2-3 knots. So, we don't think it's entirely current or wave action.

[Bigjim]

Originally Posted by Bond_vagabond

That is pretty strange. I'm no sail trim guru, but here are a few things I can think to check.

If you are using some sort of wind angle gauge, it may be out of calibration?

Some sort of assymetrical ballasting, water tank that allows water to slosh outboard on one tack but not the other?

If your prop or outboard is not on the centerline, that can make a boat behave differently on each tack.

Some aspect of your sailing location that makes you approach the wave action at a different angle with each tack, even though they are symmetrical to the wind. Often near land the predominant wave action will be from a different heading than the wind. Light boats especially can behave very differently depending on their angle to the waves, light wind making it even more pronounced.

Some asymmetrical windage, that interrupts smooth air flow over the sails on one tack but not the other.

Good luck

All good concepts, but do not apply, as far as I can tell.

1. We have telltales attached to the shrouds. So, we're pretty sure of the apparent wind angle. The anemometer is not installed yet.

2. Water and fuel tanks are all on the center line.

3. Prop is also on centerline and should react the same on either tack

4. Our race course is over a half mile offshore. There is a southerly current along the shore of Lake Michigan, which should have helped us one time, but it didn't. This boat is heavy, 10,900 lbs displacement with 5900lbs of ballast. So, light winds are our constant boogey man.

5. A possibility. But our sail telltales fly consistent with good wind flow. This is really stumping us.

FYI, everyone, the other boats we are racing do NOT have this issue. They all seem to sail well on either tack and make way even when they are close to us. So, I don't think we were in a wind hole or something weird.

[Bigjim]

Originally Posted by Cheechako

Just hard to say. One thing though, in light air, crack off your heading before you tack gaining speed, then tack. It helps keep you moving.

We would try this but the winds are so light the speed differential would not be high enough to make a difference. The boat is going 2-3 knots on the one tack. If we fall off we might be able to pick up a tenth of a knot but then lose a lot it once the rudder comes over.

[Tayana42]

No offense meant, just trying to understand, if you are making no way on your starboard tack how are you tacking over to the port tack? Did you need to backwind the jib to push the bow around?

[Bigjim]

Originally Posted by Tayana42

No offense meant, just trying to understand, if you are making no way on your starboard tack how are you tacking over to the port tack? Did you need to backwind the jib to push the bow around?

You probably didn't read the entire thread, but we dropped off the wind and jibed back around. The boat is making zero knots forward, but we were definitely being set backwards by the wind, even as light as it was.

The odd thing is that each time we went on the opposite tack, the boat would perform normally and make 2-3 knots. It's very frustrating.

[dfelsent]

You really need telltales on the luff of the jib and the leech of the main to tell you about trim issues.

There may be wind shear. Your rig may not be centered in the boat. Your keel or rudder may not be aligned. Your jib cars may not be in the same place.

But you should start with proper telltales.

[OldGreyB]

Originally Posted by dfelsent

You really need telltales on the luff of the jib and the leech of the main to tell you about trim issues.

There may be wind shear. Your rig may not be centered in the boat. Your keel or rudder may not be aligned. Your jib cars may not be in the same place.

But you should start with proper telltales.

My friends had a similar issue on their Jenneau 36i. Took them 8 months to work out the top of the mast was out of alignment. Only needed correct rigging tension to correct permanently.

[MarkSF]

You still haven’t answered the question about whether the speed is based on GPS, or a paddle.

[StuM]

Originally Posted by MarkSF

You still haven’t answered the question about whether the speed is based on GPS, or a paddle.

"the knot meter showed Zero. But it was also obvious we were not moving."

[Suijin]

I would start by retuning the rig from scratch (loosening everything and going through the entire process). That will eliminate that possibility and probably needs to be done anyway.

I’ve been on race boats where an out of tune mast will be half a knot slower on one tack, and these are boats where the tune is changed for that day’s conditions. So heavy boat in light winds...might not move at all if something is amiss.