Plotting Course to steer when beating

[Alifonz]

Here's another teaser I'd like your comments on!.......when I was doing my passage planning on my YM course I often found that when you plot a GT/Rumb line that is essentialy part of a beat to windward you often end up with a CTS (adjusted for leeway and tidal stream) that is impossible due to wind direction. When doing a practical passage plan to windward is it better to just work with a cone to target or making tack etc than try and plot a bunch of CTS's on the chart in advance which you might have to keep adjusting (after you work out the tidal stream and leeway) due to wind direction? This is another 'loophole' that I think RYA syllabus falls short of addressing......

 

[Sea Devil]

This may not be the answer you want, but assuming it is a fair distance, then you put the GPS course in-between the two points and start beating to windward - watch the track on the GPS overlaid on the line between the two points and you will soon work out the best tacks and easiest way ........... very simple - does not involve maths or chart-work which is good if you are bouncing around going to windward in a bit of a sea...

Michael

 

[Stevie_T]

You are basicaly thinking along the right lines Hobie.
If you are going to beat to windward then you will not know what course you are going to be able to steer.
The answer is to make an aproximation on your chart and check for any dangers to avoid. Then sail your best course to windward. Then you can plot a 'forward looking EP' as it were. Lay your course on the chart and allow for leeway, then add your tide, this will give you your Course over Ground and you can then check again for any dangers on that course. After a couple of tacks you then have an informed idea of what course you will make on each tack.
Hope that helps.

 

[Malcb]

When I did my passage planning on my YM course (correspondence course) I remember that one example that I had to plot was to the NE against a NE wind. I made the assumption, and stated it in the answer, that the I assumed that the vessel could not do better than 45 degrees to the wind. I then made sure that any course to steer was equal or greater than 45 degrees to the wind, and recalculated if necessary.

As it was a correspondence course, I suggested to the tutor that I would normally have stayed in port until the wind backed a little to enable an easier passage, he agreed that that is what he would have done in reality.

In my own boat I know what is the best against the wind that I can do and will plan accordingly, using the tide to my best advantage.

 

[stephenh]

If you are on a long haul don't forget the weather forecast...a later wind shift might p..s you off or cause you to celebrate depending which tack you have chosen ....

 

[Alifonz]

Thanks guys - that all makes sense to me!

 

[cardinal_mark]

Just to add one thing, I also try to keep the number of tacks to a minimum - even if this means saling that little bit further as it tends to keep the crew sweet!

Mark

 

[Twister_Ken]

Yeah, but short tacks keep the crew warm.

 

[Birdseye]

[ QUOTE ]
......................... try and plot a bunch of CTS's on the chart in advance which you might have to keep adjusting (after you work out the tidal stream and leeway) due to wind direction? This is another 'loophole' that I think RYA syllabus falls short of addressing......

[/ QUOTE ]

Do you really need an instructor to tell you that if you work out a CTS which is unachievable on the water, you might need to steer a different course?

I do not teach my students to let remove the mooring ropes before leaving the quay either. maybe I should. /forums/images/graemlins/shocked.gif

 

[fireball]

Erm - perhaps you need to go and read the original post again ... because Hobie asked a perfectly reasonable question ...

Hobie wanted to know if you want to get from A-B and the wind will not allow you to go straight there - what is a reasonable thing to do ... either work to a cone (which I'm told racing sailors do - 30 degree cone - 15 each side) or do a best achievable course to steer and work out where that would take you and do a seperate course to steer for the next leg ...

Perhaps if this is how you respond to a students question your in the wrong job....

 

[chrisgee]

I thought the original quite reasonable question also. God help Birdseye`s "students" if they have to put up with such arrogance.
Keep posting new boy we`re not all like that.

 

[john_morris_uk]

I don't think that there is any 'loophole' here at all. The answer just needs you to apply some common sense.

The course that your 'require' is often not achievable. The answer is that you sail 'Best to Windward' and take all the other factors into account. Lee-bowing the tide, forecast windshifts, etc etc.

(By the way, in reality I try to avoid long beats to windward. If we are just cruising, I will even alter our intended destination in order to avoid sailing hard on the wind!)

 

[bluedragon]

I agree totally with this answer. I had the same concern many years ago on an RYA practical course...I couldn't sail my "planned" CTS. The instructor said "are you running into danger?"...No..."do you know where you are?"..yes..."so what's your problem?"...just about sums it all up.