Protocol

A protocol is an IMO instrument that modifies or supplements an existing convention, usually adopted at a diplomatic conference and requiring its own ratification. The 1978 SOLAS Protocol responded to tanker casualties and was itself superseded by the 1988 SOLAS Protocol, which introduced the harmonized system of survey and certification (HSSC). MARPOL exists as the 1978 Protocol to the 1973 Convention, read together as MARPOL 73/78. A protocol lets states reform or extend a treaty without renegotiating the whole text, while keeping the original convention’s structure intact.