2 - Indicator figure, wind waves group
PwPw - Period of wind waves in seconds
e.g.
6 seconds is coded 06
calm is coded 00
confused sea is coded 99
HwHw - Height of wind waves in units of 1/2 metres
e.g.
0.5 m is coded 01
calm is coded 00
confused sea is coded //
- Supplementary and auxiliary
ships do not report this group