2014 © Graham Rabbitts [You are welcome to use original material from this site, but the source should be acknowledged]
New sources of digital information appear all the time. Among some of the recent candidates, here are some suggestions
1: Google Maps as an alternative to charts (e.g. for a land expedition)
2: Google Earth
(a) Street View ‘screen grabs’ to supplement gaps in your own pictures
(b) Street View panning shots and even driving along a road using screen capture software such as Movavi (see example on right)
(c) Map view grabbed from an altitude to simulate an aerial shot, either as a single image, or as a simulated flight using Movavi (or similar)
3: Copies of photos embedded in electronic charts such as C-
4: Image scanned from Newspapers (especially weather maps) or Pilot Books (especially books out of print)
5: Some chart software (e.g. Nobeltec) offer 3-
6: Data gathered by the chart plotter. For example, track recording using SOB (Software On Board) creates a database of true and apparent wind speed, boat speed, SOG, COG, depth and other parameters. These can be accessed in Microsoft Excel, and plotted using all the power of Excel. This can be useful in illustrating sudden changes of depth, or windspeed , or direction. You never know when it will be useful, but as you will probably need to record the track anyway to put on your charts the data is there, and just needs digging out. For more detail see the Charts section.
The Porstall passage video (right) illustrates a few techniques.
(Finding the supermarket in Bourgenay)