Started Sailing

To have the wind free

by Christina
(Paris, France)

"The trip from St Martin to Antigua has the wind free but the Equatorial Current forces you stay close hauled".

I am not sure about the meaning of that sentence.

Does it mean that the wind is running free but, because of the current, I must stay close hauled? Would I need to tack?

Thanks
Chris

Hi Chris

The definition of a 'reach' on Encyclopedia.com is: "As a verb, the act of sailing a vessel with the sails full and the wind free".

So I believe that if there was no equatorial current, the boat would be reaching. However the current is pushing you in another direction.

This vector means that you have to sail a different course to get to the same place. Instead of reaching (which would mean you would end up lower - in the wind - as the current would push you down), the boat must close haul, which would allow the boat to reach its actual destination (Antigua).

I think you will better understand this concept if you read about Vectors

Thank you for your interestingly mathematical question!

Best Regards
Alex Dotsch

Comments for
To have the wind free

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Mar 13, 2009

Keyword: drift
by: Han

Hi Chris and Alex,
Alex' comment is correct, although a bit sketchy; is that the reason Chris didn't react? I'll try to fill in some gaps.
The true course from St. Martin to Antigua is roughly south-east to east; the Equatorial Current (which locally is called the Caribbean Current) streams in exactly the opposite direction, parallel to the continental South-American coast. The prevailing wind-direction in that area is the north-easterly tradewind, so, superficially seen, you should be able to reach. Current and true course are opposite, so that has no direct effect on the course. However, it does slow your "speed over the ground" considerably.
Factor 2 is the sideways drift of the hull; when reaching that won't be much but the closer you're hauled the bigger the drift will be, up to 2 or 3 degrees (in this case, the wind coming in over port) to starboard, measured by your speed through the water. Let's estimate this speed at 6 knots and estimate the speed of the Current at 2 knots: the resulting speed over the ground would then be 4 knots. In the same time you cover those 4 miles over the ground, you sailed 6 miles through the water and the resulting drift must be estimated by considering those 6 miles; a lot more!
So, in order to compensate for the lost miles by drifting, you haul a bit closer, the result of which will be a lower speed and a slightly bigger drift; a real vicious circle!
That's why it is so important to have a regular fix of your position, formerly a real pain in the ass but now a question of installing a trustworthy GPS.
So you see, it could be possible that you are forced to tack.
As I don't know the exact figures to fill in the answer to this interesting question, I hope to have made clear that reaching, anyway, cannot be realised if you want to arrive in Antigua.

Best wishes for the rest of your trip,
Han

Mar 13, 2009

Thanks guys!
by: Chris

Thanks to both of you Alex and Han. Both your answers were enlightning.

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