PRACTICAL

In some parts of the world the last survey was done in the early 1800s

SPECIAL REPORT

JANNEKE KUYSTERS ON GEOREFERENCED SATELLITE IMAGERY

Every cruiser is familiar with that tingle of doubt: is my chart really up to date, and is that shallow bank still in that location? Careful ‘eyeball’ navigation in tropical waters has become a lot easier thanks to satellite overlays on digital charts, and for those sailing off the beaten track there are simple tools to make your own overlays.

Of course shipping routes for commercial traffic are well charted; as a necessity they have been surveyed for well over a 100 years. But those little nooks and crannies where we love to sail or anchor? In popular cruising areas like the Mediterranean or the Caribbean, chances are that your digital and/or paper charts will be a great help in reaching those spots safely, because of the yachting and/or commercial traffic there.

But when visiting more remote spots you may notice that regular charts for chartplotters differ in accuracy per region. One supplier is often best in one area, but another might excel