DWD marine barograph (photo Deutscher Wetterdienst)
The amount of the pressure tendency and characteristic of the pressure tendency in the past
three hours is obtained from a marine barograph, preferably an open-scale instrument
graduated in divisions of 1 hPa, or from an integrated electronic barometer-barograph with a
digital output.
NOTE (supplementary and auxiliary ships only)
- Supplementary and auxiliary
ships do not report the amount of pressure tendency and the
characteristic of the pressure tendency