Planning a Route on Garmin Basecamp

How to plan a motorcycle route on Garmin Basecamp using an iMac or MacBook laptop. Waypoints are the answer to keep to the route during your adventure. After almost 10 years of motorbike tours around Europe, with winters spent plotting routes with Garmin MapSource and then Basecamp, finally I splash out and buy an iMac. Plot a route through the Pyrenees and before I even reach Brittany Ferries at Plymouth my super dooper new BMW Navigator VI has been telling me for 300 miles that I am 'off route'. The iMac is not the same as the PC! Now I have discovered that I was doing everything wrong. If you have never dared to plot a route spare 20 minutes and watch!