RCD Categories

Unless you want to cross the channel, Cat D is enough for most inland waters, though large waters, such the Ijsselmeer, great rivers and Etang de Thau, would need to be appreoached with care.  Cat C is generally preferable to go anywhere inland.

Category

Scope

Wind Strength

Wave Height

Comment

A

Ocean

8 +

< 8m

Designed for extended voyages where conditions may exceed wind force 8 (Beaufort scale) and significant wave heights of 4 m and above but excluding abnormal conditions, and vessels largely self-sufficient*

B

Offshore

< 8

< 4m

Designed for offshore voyages where conditions up to, and including, wind force 8 and significant wave heights up to, and including, 4 m may be experienced*

C

Inshore

< 6

< 2m

Designed for voyages in coastal waters, large bays, estuaries, lakes and rivers where conditions up to, and including, wind force 6 and significant wave heights up to, and including, 2 m may be experienced*

D

Sheltered

< 4

< 0.3m

Designed for voyages on sheltered coastal waters, small bays, small lakes, rivers and canals when conditions up to, and including, wind force 4 and significant wave heights up to, and including, 0,3 m may be experienced, with occasional waves of 0,5 m maximum height, for example from passing vessels*