If your destination is directly to windward, how much more time to allow...

[Babylon]

1. If you're under sail and will be tacking?
2. If you're motor-sailing as close as you can to the wind but will still have to tack eventually?

Assume no tide.

 

[AuntyRinum]

How far are you travelling? How close do you point? What is your average speed?

 

[lpdsn]

1. If you're under sail and will be tacking?
2. If you're motor-sailing as close as you can to the wind but will still have to tack eventually?

Assume no tide.

It depends a huge amount on the boat. The VMG on the GPS is a very useful tool.

 

[temptress]

1. If you're under sail and will be tacking?
2. If you're motor-sailing as close as you can to the wind but will still have to tack eventually?

Assume no tide.

How far are you going? I wait until the wind changes or go somewhere else

 

[johnphilip]

1. If you're under sail and will be tacking?
2. If you're motor-sailing as close as you can to the wind but will still have to tack eventually?

Assume no tide.

1. If the tide is with you add 50% to the downwind time, if the tide is on the nose then double the time. This is a reasonable assumption even with a pretty good windward performance. It will also be colder and could seem even longer.
2. Depends on the boat, could be nearly as long but noisier.

 

[VicS]

1. If you're under sail and will be tacking?
2. If you're motor-sailing as close as you can to the wind but will still have to tack eventually?

Assume no tide.

It will depend on how close to the wind the boat will sail without loss of speed and the amount of leeway the boat will make


Maybe a boat that sails close to the wind and makes little leeway will do it in under 50% extra time but some old tubs will take very much longer.

The mistake can often be to attempt to sail too close to the wind. Not only will the speed fall but the leeway will increase.

Motor sailing helps because you can keep the speed up and that will also help to keep the leeway down.

 

[Seven Spades]

Simple boat speed x COS (bearing difference) Bearing difference is the difference in angle between where you are going and where you want to go. So for example if your destination is way 270 degrees but you can only sail at 310 degrees and you boat speed is 6knts then your effective speed is down to 6 x COS (40) = 6 x 0.766 =4.6knts you can work this out on any mobile phone.

 

[Babylon]

How far are you travelling? How close do you point? What is your average speed?

It depends a huge amount on the boat. The VMG on the GPS is a very useful tool.

How far are you going? I wait until the wind changes or go somewhere else

1. If the tide is with you add 50% to the downwind time, if the tide is on the nose then double the time. This is a reasonable assumption even with a pretty good windward performance. It will also be colder and could seem even longer.
2. Depends on the boat, could be nearly as long but noisier.

60NM Needles to Cherbourg in a Southerly F4, so cross-tides (and winds tangential to tide rather than over- or with-tide).

Don't point very close at all (27ft, heavy, long-keeler), say 50 degrees plus 10 deg leeway. Average speed through water 4.0/4.5kts kts on a fine-reach/close-haul under sail assuming any short seas don't stop us too much. Bottom currently clean, and windvane self-steering pretty good at its job. Can alternatively maintain 5.5kts motor-sailing a bit closer to windward with the autohelm steering.

With at least a F4 on the beam, we'd easily sail it all at 5.0kts plus and be there in 12 hours. But with a F4 right on the nose, definitely motorsailing at a wet, windy and noisy 5.5kts, and lee-bowing the tide (first on one long tack, then on the other), I reckon we'd point at least 10 deg higher. However say 40 degrees including leeway isn't a huge difference in angle to windward, so I'm going to assume at least a 50% increase in passage time: 18 hours!

Maybe we'll be heading West instead...

 

[dunedin]

Another for - it depends

In light winds (below 7 knots wind speed) I reckon we are probably faster upwind than directly downwind due to the apparent wind factor.

And many seemingly inefficient boats seem to be faster upwind than down - 7 knots VMG (though with sails furled!).
We don't manage that

 

[Seven Spades]

60NM Needles to Cherbourg in a Southerly F4, so cross-tides (and winds tangential to tide rather than over- or with-tide).

Don't point very close at all (27ft, heavy, long-keeler), say 50 degrees plus 10 deg leeway. Average speed through water 4.0/4.5kts kts on a fine-reach/close-haul under sail assuming any short seas don't stop us too much. Bottom currently clean, and windvane self-steering pretty good at its job. Can alternatively maintain 5.5kts motor-sailing a bit closer to windward with the autohelm steering.

With at least a F4 on the beam, we'd easily sail it all at 5.0kts plus and be there in 12 hours. But with a F4 right on the nose, definitely motorsailing at a wet, windy and noisy 5.5kts, and lee-bowing the tide (first on one long tack, then on the other), I reckon we'd point at least 10 deg higher. However say 40 degrees including leeway isn't a huge difference in angle to windward, so I'm going to assume at least a 50% increase in passage time: 18 hours!

Maybe we'll be heading West instead...

OK so that 5.5 * COS (40) = 4.2 knts over 60 miles = 14 hours 17 minutes

 

[Skylark]

60M to windward doesn't fall within my definition of yacht cruising. I'd go somewhere else and save Cherbourg for another day, with more favourable conditions.

 

[Babylon]

Simple boat speed x COS (bearing difference) Bearing difference is the difference in angle between where you are going and where you want to go. So for example if your destination is way 270 degrees but you can only sail at 310 degrees and you boat speed is 6knts then your effective speed is down to 6 x COS (40) = 6 x 0.766 =4.6knts you can work this out on any mobile phone.

That's useful, thank you. So I'll apply that to my figures above (ignoring lee-bowing the cross-tides):

Sailing at 4.0kts at a bearing difference of 60 deg (50 deg maintainable plus 10 deg leeway):
4 x COS (60) = 4 x 0.5 = 2kts, therefore 30 hours to cross 60NM to Cherbourg.

2. Motorsailing at 5.5 kts at a BD of at least 45 deg (35 deg to wind plus 10 leeway):
5.5 x COS (45) = 5.5 x 0.7 = 4kts appx, therefore 15 unpleasantly wet, heeled and noisy hours to cross

No brainer, then...

 

[capnsensible]

Just go double and be pleasantly surprised if it takes less.

 

[Roberto]

Just go double and be pleasantly surprised if it takes less.

+1

 

[johnphilip]

Simple boat speed x COS (bearing difference) Bearing difference is the difference in angle between where you are going and where you want to go. So for example if your destination is way 270 degrees but you can only sail at 310 degrees and you boat speed is 6knts then your effective speed is down to 6 x COS (40) = 6 x 0.766 =4.6knts you can work this out on any mobile phone.

And use the mobile phone to give you the wave height and frequency and % of speed loss due to wave action.
Download the forecast to check whether the wind is dead on the nose or offset giving long tack, short tack.

In preplanning terms only a rough approximation is possible, once out there see the time of arrival on your plotter.

 

[Neil_Y]

In practice you re asses as you go, as wind strength/direction, sea state and crew ability to steer a good course may vary quite a bit.

 

[lw395]

Just go double and be pleasantly surprised if it takes less.

Or add 24hrs to account for a leg down to Weymouth and a night in the club there?
If it really is a good Southerly, you could make Dartmouth in one tack.

 

[Babylon]

Or add 24hrs to account for a leg down to Weymouth and a night in the club there?
If it really is a good Southerly, you could make Dartmouth in one tack.

And its likely to be raining! Weymouth and back over three days is certainly achievable - will just have to make a final decision early Sat AM at anchor, depending on latest forecast.

 

[Tomahawk]

If you do make it .. the beer will taste all the more sweet…



OTOH, I wold think your destination is in the wrong place….. A gentleman etc etc..

 

[Twister_Ken]

Forget Cherbourg. Go to St Vaast or Alderney, and get a bit of a slant to help you. Or come out at the east end of the Solent, and the course won't be dead to windward.