Question: I’m planning a cruise of the west coast of Greenland. For charts I have the choice between C-MAP electronic charts running on Furuno Navnet with Maxsea on a PC and Danish paper charts. Which would you recommend?
Answer: In a perfect world, both. Let me explain why: Although the C-MAP electronic charts are pretty much exact copies of the Danish paper charts and are the standard for commercial vessels in Greenland, the datums on both are often, in fact usually, inaccurate.
This means that you can’t rely on the position of the boat icon on a plotter to keep you off the rocks and instead must navigate traditionally by using ranges and bearings on land features.
During my trip to Greenland in 2006 as guide/navigator on the 88’ Jongert Vivid I had both paper charts and C-MAP on Maxsea available (it’s so nice when someone else is paying). I found that, although Maxsea has the capability to plot ranges and bearings, I was much faster and more accurate plotting on paper. Also, the larger area that I could see on the paper chart, without zooming in and out, helped me to stay oriented to my surroundings and position, which is vital in Greenland. I should say that I was relatively new to Maxsea at the time, compared to 40 years of navigating on paper, so this could be more my failure than a systemic one.
The two commercial vessels I visited that relied exclusively on Maxsea/C-MAP both had two very large screens allowing them to keep both an overview and detail view available at all times without zooming. In addition, I suspect most of their voyages are between the larger ports in Greenland where the datums are usually, although by no means always, more accurate than places off the beaten path where we like to go.
On the plus side for Maxsea/C-MAP, most of the charts have a datum correction amount that can be applied in the software. I chose not to do this since the correction is different for every chart and I was worried that I would either forget or not have time to change it each time we moved to a new chart. I was also not totally confident that all the corrections provided would be accurate.
In summary, I can only tell you that I would not rely solely on electronic charts in Greenland and if forced to choose only one system, would opt for paper. However, if you are totally comfortable with your electronic navigation system and your ability to navigate safely with it in a place where the datums can’t be trusted, you may decide that my belt and suspenders approach is overkill.