B&G Deckman - Manual (Page 138)

Making wind or current Grids
9.11
Note. As usual, a positive number indicates North or East; a negative
South or West. In GRIB files, however, positions are in the form degrees
and decimals of a degree, not degrees and minutes.
Selecting File>Save in Grib.exe automatically saves the data in a format
readable by Deckman (indicated by the file extension .cgf, see GRIB
routing below). You will be prompted to select which data from the
GRIB you wish to save (wind, current or everything else). If you wish to
save more than one type of data, you must select Save As after the first
time.
Making wind or current Grids
This function gives you very flexible facilities for entering your own
wind or current forecasts for use in Deckman’s routing calculations. You
essentially ‘create’ your own weather map specifying data for different
positions on the chart, and Deckman then interpolates between these by
triangulation. The principles of using the function are outlined below,
followed by some tips as to how the function is best used and a few
examples of what is possible.
Forecast type
(code number)
Date and time of forecast Time between forecast
and present data
Figure 9.7