Understanding VMG VMC

[Mercator]

I'd like to make better use of the info given. Would I be right in saying that if velocity made good (VMG) = Velocity made course (VMC) , I am making the best forward progress on my course. Add to that, that the heading of Best to waypoint ( BTW) is acutually the end result. thx

[Tangent]

Hi!
Quick correction: BTW actually stands for Bearing To Waypoint. It is just the heading you would take on a direct line to your waypoint, and it is not always the "Best" route

For example, if the wind is coming from 30* and the BTW is at 30*, you will not make headway if you set your heading to 30*. Instead, you should choose a course that maximizes VMC (your velocity in line with the waypoint), which in this case will also maximize VMG (upwind velocity).

But, a good course might not always maximize both VMC and VMG at the same time.
Ex#2: The wind is coming from 0*, and your BTW is 90*. To maximize VMC you should travel with a heading of 90*, but that means VMG will be 0 kn, since you won't be making any progress upwind.

So, in any situation, the best course to travel is the one that maximizes VMC and doesn't result in a collision with boats or land. To max out VMC, you have to play around to make the best use of the available winds and current, as well as sail trim.

I hope that helps! :)

[Mercator]

Thank-you , always open to advice. Another tip I had read was , just because the boats pointing that way doesn't mean thats where we're headed. Cheers :-)

[Capt.Jamesbloke]

Well put Penitent Tangent! :)

[DiscoInfidel]

Also, my experience so far indicates each boat has an optimal AWA when close hauled. This can change some with changing wind strength and sea conditions. That being said doing simple winward and run sessions where you choose and "optimal" AWA and chart VMC/VMG has proven helpful. If you're a complete nutter like me you may find yourself keeping a log book of these sessions to try and gain a deeper understanding...

[Mercator]

Nutters unite. Actually I have been noting the above and found the 38 crusier better at 28 to 29 AWA. The log is a good way of learning.