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Virtual Clipper RTW 2015-2016

Clipper Round the World Sailing

Sailing at Perdepera, Sardinia

Americas Cup sailing 2010

How does a sail work

Find your lat and long

Use of magnetic compass

Great circle azimuth bearing and range

Sailing in Lemnos

Clipper Ocean Racing (weekend)

Clipper 60 Ocean racing - the sails

Sailing holiday at Lakitira

Sailing at Perdepera, Sardinia

Deg, min, sec calculator

Finding north and pole star

 VMG calculator for Clipper 70 with PRO or BASIC sails

This page is experimental and may give wrong results. It is still under development. Results may be in error.

Comments please to

When sailing upwind or downwind the best velocity made good (VMG) occurs at approx 42-55 deg either way from directly upwind or approx 40 deg either way from direct downwind. Note that these angles refer to true wind angles.

Depending on the polars there may be other desired directions where sailing at a slightly different angle gives a better VMG.

Select sail type: Pro   Basic

Select wind speed knots

Input positive numbers only

Wind origin Desired
Great circle course
Boat speed on desired course Wind Angle on desired course

Best Wind angle Best VMG Boat speed
Best courses VMGs  
Wrong tack course Wrong tack VMG Wrong tack Wind Angle

Polars used assume boats as of 25 August 2015. If using basic sails option then best choice of Jib (Foc) or Spinnaker (Spi) is assumed. If using Pro sails option, then it assumes best choice at any time of the 5 Pro sails.

Update 20:20pm 28 August.  The published polars (as of 18th August) have been updated. I have just worked out the new ones and added them into the program above. If anyone checks some of the outputs, please tell me. I've tested some samples and it seems OK but you can never tell !!

If anyone uses this page please tell me and send your thoughts, even if you think it is rubbish!.

I will add your comments below.


► Page created 2011, amended 1 October 2018