Why is my tack angle so wide?

[contrail]

If you know San Francisco Bay, you know exactly what was happening, which is what Jim, others, and myself have been saying. The OP has now confirmed that max flood was at noon, and they reached the "gate" (which is what everyone in SF calls the Golden Gate Bridge, not a tidal gate) at 1:30 PM. So, they were sailing just before and after max flood, which is really, really strong. Can be six knots. So they were going up-current at precisely the wrong time. And they experienced the normal result. When I used to live in the South Bay, I could only sail up to the central bay every other weekend. On the alternate weekends, it was a no-go, with just sailing back and forth, even though hard on the wind. I doubt that analysis of sail trim, boat type, or any of the other normal questions has anything to do with what the OP experienced, at all. Best proof is that he can replicate the experience, just as he can avoid it, by consulting the tide tables.

I learned this the first time I went OUT the Golden Gate, ignorant of tide tables, etc. All was well until I tried to come back in, except I was facing max ebb, not max flood. I had plenty of wind, my sails were trimmed correctly, and at one point I even ignorantly started the engine! But I sat right next to one of the channel markers for an hour. Then I gradually started to move, but took another hour to get to the next buoy. After that, I started to move better and better, but at one point I found myself wondering if I would EVER get back in. Lesson learned and well remembered.

[Be Free]

The short answer to your question is "tidal current".


The instrument that you are using to determine your go/no-go zone is not your best tool. Your tell-tales and your sails themselves will give you a much more accurate indication of whether you are pointing too high.



The no-go zone on your instrument may have been set correctly for your boat when it was installed (unlikely) but all it takes is one seagull sitting on it to knock it completely out of adjustment.

[bailsout]

I sailed my Sabot for the first time in two years this last week and learned the importance of a tight outhaul when beating. It took me awhile to notice it was slipping in the cam cleat.

[sailingchiro]

Originally Posted by TrentePieds

It seems from you post that in lighter airs you have a smaller tacking angle. That is common to many boats, so one of the things we need to know is just exactly what boat you sail.

The first thought that occurs to me is that you were trying too hard. You were probably over canvassed and over trimmed. One indicator of the former is angle of heel, so perhaps you can tell us, once you've told us what the boat is, how hard you made her heel, nd what amount of canvas you carried. As far as over-trimming goes, just ease sheets till you get a suggestion of 'loosing your luff" while you are holding your heading. Then harden sheets JUST enuff to kill the luff.

The trick is to keep 'er footing. Once you lose speed you will also loose tacking angle.

So tell us what boat it is.

TrentePieds

As far as over-trimming goes, just ease sheets till you get a suggestion of 'loosing your luff" while you are holding your heading. Then harden sheets JUST enuff to kill the luff.

This is the best advice for most sailors. So many people overtrim and put so much pressure on the rig and sails killing speed.

[FabioC]

You should tune your sails and rig so your boat can point higher.
The main variables to work on are forestay tension and jib sheet angle.
If your boat has a backstay, get more tension on it, so the forestay will sag less and the boat will point better.
If your jib sheet lead has tracks, play with it, by bringing the lead forward and in-board. If the lead is fixed, rig a line to play as "barber-hauler" and bring the jib sheet angle more in-board somehow. If the jib is cut too deep on the luff side, there is not much you can do other than have it recut, but playing with the controls will improve things somewhat anyway.
For the main, depending on the wind, try to flatten it, get some vang and outhaul on and see if that helps pointing higher.
If possible, take as a reference another boat going up-wind, follow them and see if you are pointing higher or lower than them.

[DEAN2140]

"Yep, they were goin' up tide, but what I was talking about was the statement that it was only when going about that the tidal effect was to be noted. This is a common belief, associated with thoughts about "lee bowing"."

Jim is correct. This is a common misconception, even among seasoned racers. I remember a spirited conversation along these lines among veteran Mercury sailors aboard my J105 that having the current strike one side of your bow "lifted" the boat on that tack. Wrong. Think of standing on a large carpet that is being pulled. You will move in the same direction regardless of how you position yourself. The same with a boat.

[guyrj33]

Originally Posted by DEAN2140

"Yep, they were goin' up tide, but what I was talking about was the statement that it was only when going about that the tidal effect was to be noted. This is a common belief, associated with thoughts about "lee bowing"."

Jim is correct. This is a common misconception, even among seasoned racers. I remember a spirited conversation along these lines among veteran Mercury sailors aboard my J105 that having the current strike one side of your bow "lifted" the boat on that tack. Wrong. Think of standing on a large carpet that is being pulled. You will move in the same direction regardless of how you position yourself. The same with a boat.

The OP described a situation where the current and the wind were flowing in the same direction and the boat was being set by the current. Greatly restricting forward progress.
I think saying the current affects all points of sail equal is too simplistic an explanation for this situation.
Imagine the wind was beam to the direction of the current, the boats progress over ground and against the current would have been very different.
Now imagine the wind is farther forward of the beam, say 50 degrees apparent and strong enough to move the boat against the current. If you had the choice of the current hitting the fin keel at 5 degrees from windward or five degrees from the leeward side which would give you the most lift toward the wind. This is a purposefully narrow example.

[Capt. Ray]

Originally Posted by LakeSuperior

An opposing current will have a dramatic effect on your tack angle.

Current will not affect apparent wind or "tack angle", only the vector over ground.

[Stu Jackson]

Originally Posted by Yangyangyyy

See attached GPS trace. We were trying to beat 25 knots wind (normal for San Francisco bay) to go out of the Golden gate bridge.

On the way out, we had to do a total of 14 tacks to reach the gate. >>>>>>>>>>>>
>>>>>>>>>>>>>>>>

I think normally I see the tack angle to be about 90 degrees. Why is it so wide today? Is it due to the flood (tide water running into the bay)

You would have to have a truly remarkable boat to do 90 degree tacks, but who am I to argue with you? Heavy winds will affect your angles. I sailed The Bay from 1978 to 2016, from 98 to 16 in this boat and raced a lot from 1999 to 2006.

14 tacks? Were you tacking up The Cityfront? Even with heavy afternoon winds on a flood, I've been able to lay the D&E span of the Bay Bridge to Sausalito in one port tack, it is doable. Depending on the size of the flood, sometimes a tack at Harding to the south and then back up again works.

But having sailed my boat for like forever, I know that my optimum tack angle is 120 degrees, far off 90 degrees. I planned accordingly.

Good luck.

[ChrisJHC]

Originally Posted by Stu Jackson

You would have to have a truly remarkable boat to do 90 degree tacks, but who am I to argue with you? Heavy winds will affect your angles. I sailed The Bay from 1978 to 2016, from 98 to 16 in this boat and raced a lot from 1999 to 2006.

14 tacks? Were you tacking up The Cityfront? Even with heavy afternoon winds on a flood, I've been able to lay the D&E span of the Bay Bridge to Sausalito in one port tack, it is doable. Depending on the size of the flood, sometimes a tack at Harding to the south and then back up again works.

But having sailed my boat for like forever, I know that my optimum tack angle is 120 degrees, far off 90 degrees. I planned accordingly.

Good luck.

This implies that the closest you can point to the wind is 60 degrees on one tack and then 60 degrees on the other tack.
Are you sure that’s what you mean?
Every boat I’ve been on has been able to achieve a 90 degree tack (and some even less).

[George_SD]

Another thing is your standing rigging/spars - if it is not dialed in, it will make your tacks wider. You also want to be in the groove on both sides to see what's your most narrow tack.

Beneteau is OK, but they are not nearly as efficient going upwind as some other boats, especially the older ones.

[waterman46]

Originally Posted by TrentePieds

Ah, yes, forgive me OP was talking about his TRACE!

Well, to me "tack angle" is the difference in HEADING when you are sailing properly on one tack and then go about to the other tack and sail properly on this new tack.

That has nothing to do with TRACE whatever since trace must necessarily be influenced by tidal current.

Best not to get too fixated on the Garmin :-)

TP

Yes! Forget about GPS, and forget about moaning how long it takes to get to the Gate. Next time don't fight the flood.

If your boat is performing well in terms of speed through water and true wind angles, that's what you want to optimize. Do you have wind instruments? All you need to look at is the angle of apparent wind and try to optimize your speed and sail trim to get a sense of how close to the wind you can sail. True wind angles are even better, and can be obtained from chartplotters with the right software and inputs from wind instrument (apparent wind angle and apparent wind speed) and boat speed through the water (not GPS).

But it is more fun to simply follow another sailboat about your size that seems to tacking out the Gate, and see how you do with respect to him.
Tack and follow in his wake at a respectful distance, see how he is pointing and gaining or losing on you. Much easier to judge your boat's performance against other boats than with your head down on a chartplotter.

[MarkSF]

Originally Posted by Capt. Ray

Current will not affect apparent wind or "tack angle", only the vector over ground.

It will if he's measuring the tack angle by looking at the GPS tracks afterwards, or gauging simply by the fact he had to do 14 tacks. But I think we're saying the same thing.

[TrentePieds]

Quote: "Do you have wind instruments?"

EVERYBODY has "wind instruments" - the are called "ears" :-0)!

I suspect that people who claim they can do a 90º tack in a garden variety cruising boat, are neither using their ears nor looking at their steering compass. You can certainly do a "faux" 90º tack if you are not worried about keeping 'er "footing".

TP

[Happ]

Originally Posted by Yangyangyyy

See attached GPS trace. We were trying to beat 25 knots wind (normal for San Francisco bay) to go out of the Golden gate bridge.

On the way out, we had to do a total of 14 tacks to reach the gate. My main issue is that the angle between our 2 tack directions is very large, at about 120 to 145 degrees. As a result we did not gain much distance westward between tacks. But we already were sailing upwind as much as possible , close hauled, the wind needle pointing right on the edge of the no-go zone wedge on top of mast.

I think normally I see the tack angle to be about 90 degrees. Why is it so wide today? Is it due to the flood (tide water running into the bay)

I’ll bet the tide was coming in or you were overpowered thus side slipping because the keel was to horizontal.