San Blas Navigation

Navigation in the San Blas

99% of the time on Itchy Foot we use Navionics charts for navigation, along with continual sanity checking from the depth sounder, eyeballs, and compass bearings. Before coming to the San Blas I was told that Navionics is not reliable and I should find and alternative source of charts. Most recommendations favoured ‘The Panama Cruising Guide’ by Eric Bauhaus and there were plenty of pirate copies of both his guide (pdf) and associated charts (kap files) to be found in Grenada and the ABC islands. When it became clear that we would actually be going to the San Blas and how important (and well written) his guides are, we decided to buy an original copy of the Panama Cruising Guide.

The next question became how to use the information in the book. Obviously we can the anchorage guides and figure out where we would like to go. In addition to that we had good advice from Blue Zulu and other cruisers who has passed before us as to their favourites (and importantly why!) The cruising guide also has waypoints which I can enter into my existing navigation software and just bounce from waypoint to waypoint. And as I mentioned before, someone has been kind enough to scan in all the charts from The Panama Cruising guide (4th edition) and turn them into KAP files which can be read by some charting applications.

What I really wanted was to have a plotter with the Bauhaus charts. The first and easier way to do this is with my Mac and OpenCPN which will talk to the GPS onboard Itchy Foot. OpenCPN will happily show the Bauhaus charts as well as CM93 charts which I already had installed as a backup. But I don’t like popping up and down the stairs to check the chart and didn’t want to put the laptop near the helm. So, I wanted an iPad solution (OpenCPN works on Android but not iPad). Next step was to get SEAiq Open which is navigation software for iPad which will read KAP files. Unfortunately the developer has disabled the ability to show CM93 charts (as they are pirated) but still, this allowed me to have Bauhaus charts at the helm and on two devices.

So far, and we’ve not been that far yet, the Navionics charts are almost useless. Both completely lacking features: islands, rocks, depths, to name but a few things that just don’t show up. Bauhaus is far better, but still not perfect. They seem to capture most of the features of the area and so far all the charted depths are accurate. However, it is far from perfect. The chart (7-66) we used to try (and failed) to enter Suledup is significantly different from actual GPS positions. The interesting thing is that if you read the book there is a warning on this chart that the lat/long grid is incorrect, but if you only used the KAP files you would get no such warning.

The entrance of Obaldia is accurate, as is the entrance to Puerto Perme and Isla Pinos. Puerto Escoses also seemed accurate. In all of the above cases the Navionics charts has significant errors. We’ll keep track over the coming weeks and update this post when we get to internet land, but already I would not consider cruising the eastern (I believe western is better) without Bauhaus charts.

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