Page to test our Google Maps coding
The "+" and "-" buttons at the top left of the map control the scale of the map and hence the amount of detail shown. The PURPLE track shows the Great Circle route i.e. the shortest path available. The BLUE track looks shorter but is not. It does, however provide the compass direction or bearing of the destination from the start. Note that the shortest route from New York to Penzance would result in flying over (or trying to sail through) Nova Scotia, Newfoundland and Land's End. See www.csgnetwork.com/marinegrcircalc.html for a good explanation.
www.barrymerchantseamen.org.uk 
