Class notation R4 defines a service area restriction.

Purpose

The notation is offered to vessels that are designed for a particular service. The notation is generally applicable to small vessels and normally less than 100 m long.

Benefits

• adjustment of design loads based on the limited service area

• retaining the same safety level as for vessels operating without service area restrictions is retained

• may result in reduced building or conversion costs

Features

This notation indicates that the service area is restricted to a distance in nautical miles from the nearest harbour or safe anchorage in relation to the seasonal zones stated below:

Winter: 5
Summer: 10
Tropical: 20

The seasonal zones are as defined in the International Conference on Load Lines, 1966, Annex II.