How much longer is a beat than a run
- Thread starter Twister_Ken
- Start date
Sybarite
Well-Known Member
It would be easy to prepare a graph and keep it posted for interpolating intermediary distances at a glance.
Twister_Ken
Well-Known Member
It would, but remembering rhumb line x 1.25 is easy enough. It's only a rough guide for planning longer passages when the wind is on the nose.
maxcampbell
Well-Known Member
I drew this out on graph paper a couple of weeks ago, and measured the lines. At 90 deg tacking angle I reckoned you sailed 1.5x the rumb line distance, and at 100 deg tacking angle (I do sail a gaffer) 1.6x. (ie 6.6% slower)
The relatively small difference has got me easing off, unless I can luff hard into the puffs.
Lee-bowing I always understood as being when you get an adverse tide on your lee bow, which then allows you to lay far higher up the river than having it on the weather side. In such circumstances it's certainly worth pinching & going much slower through the water.
The relatively small difference has got me easing off, unless I can luff hard into the puffs.
Lee-bowing I always understood as being when you get an adverse tide on your lee bow, which then allows you to lay far higher up the river than having it on the weather side. In such circumstances it's certainly worth pinching & going much slower through the water.
jimi
Well-Known Member
personally I can't point as high on both tacks (it was once explained to me as a consequence of sheer) so i tend to sail fast and free on one tack and then point as high as I can on the other. Wave direction also makes a big difference to what is the "making" tack.
DJE
Well-Known Member
I seem to remember my yachtmaster examiner saying "If you can't lay your course double your expected passage time."
In that and on a few other points he made there seemed to be underlying theme that went something like "Don't get the crew's hopes up, if you tell them you'll be in at eight and you're in at six they think you're brilliant, if you tell them eight and you're in at ten they won't come sailing with you again."
In that and on a few other points he made there seemed to be underlying theme that went something like "Don't get the crew's hopes up, if you tell them you'll be in at eight and you're in at six they think you're brilliant, if you tell them eight and you're in at ten they won't come sailing with you again."
flaming
Well-Known Member
Just because their sails are let all the way out, doesn't mean they are pointing the boat straight downwind.
It's pretty clear from your photo that they are not. They'll be somewhere around the 170-175 angle I would guess.
Lakesailor
Well-Known Member
Oh well, you know best.
Me and Mental Puse must have been mistaken.
Me and Mental Puse must have been mistaken.
snowleopard
Well-Known Member
Leaving aside special running sails, a bermudian rig operates in three modes:
Close hauled, where the sails are flattened and there is an optimum flow over the sails with a full slot effect. This operates also on a close reach
Broad reach where the main is pressed against the shrouds and the headsail is a deep curve. Both sails are partially stalled but speed is better than close hauled because the resultant force on the sails, though less, is more in the direction of travel
Running where the sails are fully stalled and the drive is obtained by stopping as much wind as possible.
Whether aiming off is best depends on the relative amounts of drive in the last two states. For a lot of boats the running configuration is inefficient because the sails simply can't be spread at right angles to the wind. The question is which has the greater efficiency losses?
Look at this configuration:
In this instance on a broad reach the sails are still in laminar flow so operating with the same efficiency as close hauled. With the same sail settings on a run, the maximum possible amount of wind is stopped. In practice, though the broad reach is substantially faster than a run, the run actually gives a better VMG.
noelex
Well-Known Member
When comparing sailing into wind with downwind the distance is the only factor. The apparent wind will be higher sailing into wind.
In light conditions this can make sailing into wind less of a penalty than it would be assumed looking only at the relative distances involved.
In light conditions this can make sailing into wind less of a penalty than it would be assumed looking only at the relative distances involved.
john_morris_uk
Well-Known Member
Ignoring all the maths, I know the real answer.
Sailing upwind FEELS like it takes twice as long as sailing downwind - and in some conditions it feels like three times further.
As we all mostly sail for pleasure that's the important answer.
To the poster who said that they tack through 70 degrees, are you sure? There are a very few very racy boats that can achieve that in flat water and the right conditions, but its rarely the fastest way to get to windward. Foot off a little for a radical increase in boat speed for only a small increase in the distance you have to sail gets you there faster - although you have to 'sail your polar's' to get optimum performance. This is in conjunction with a feel for what the wind and waves are doing to your boat speed. In other words although for a given wind speed there will be a predicted optimum wind angle and predicted boat speed, sometimes you can afford to pinch a fraction and sometimes you need to foot off slightly to gain enough power to sail through the waves.
Personally I have a suspicion you mean you tack through 70 degrees of apparent wind. When sailing at 45 degrees to the true wind, the wind direction indicator usually points to about 35 degrees. You actual tacking angle will be more like 90 degrees plus or minus.
Sailing upwind FEELS like it takes twice as long as sailing downwind - and in some conditions it feels like three times further.
As we all mostly sail for pleasure that's the important answer.
To the poster who said that they tack through 70 degrees, are you sure? There are a very few very racy boats that can achieve that in flat water and the right conditions, but its rarely the fastest way to get to windward. Foot off a little for a radical increase in boat speed for only a small increase in the distance you have to sail gets you there faster - although you have to 'sail your polar's' to get optimum performance. This is in conjunction with a feel for what the wind and waves are doing to your boat speed. In other words although for a given wind speed there will be a predicted optimum wind angle and predicted boat speed, sometimes you can afford to pinch a fraction and sometimes you need to foot off slightly to gain enough power to sail through the waves.
Personally I have a suspicion you mean you tack through 70 degrees of apparent wind. When sailing at 45 degrees to the true wind, the wind direction indicator usually points to about 35 degrees. You actual tacking angle will be more like 90 degrees plus or minus.