The 1981 amendments
Adoption: 19 November 1981
Entry into force: 1 June 1983

A number of rules are affected but perhaps the most important change concerns rule 10, which has been amended to enable vessels carrying out various safety operations, such as dredging or surveying, to carry out these functions in traffic separation schemes.

The 1987 amendments
Adoption: 19 November 1987
Entry into force: 19 November 1989

The amendments affect several rules, including rule 1(e) ? vessels of special construction: the amendment classifies the application of the Convention to such ships; Rule 3(h), which defines a vessel constrained by her draught; Rule 10(c) ? crossing traffic lanes.

The 1989 amendments
Adoption: 19 October 1989
Entry into force: 19 April 1991

The amendment concerns Rule 10 and is designed to stop unnecessary use of the inshore traffic zone.

The 1993 amendments
Adoption: 4 November 1993
Entry into force: 4 November 1995

The amendments are mostly concerned with the positioning of lights.

The 2001 amendments
Adoption: 29 November 2001
Entry into force: 29 November 2003

The amendments include new rules relating to Wing-in Ground (WIG) craft. The following are amended: