Electronic charting in Halong Bay, Viet Nam on 20 May 2007

During a tour of Halong Bay, near Hanoi, Viet Nam, I had the opportunity to use an electronic charting program (MaxSea with cm93 charts, version 2005) and a 'hockey puck' GPS to track some of the courses of the tour boat we were aboard.  Perhaps this is the first time it's been done?


This is the area.

And here are the tracks.

In more detail here..

As you can see, the charts are in considerable error.  The actual position of the tracks is about 0.3 NM to the southeast of the displayed track.

If and when this area is opened to cruising yachts it will be a matter of concern until corrections are made to the existing electronic charts.