Regulation 37 of MARPOL Annex I requires that oil tankers of 150 gross tonnage and above and all ships of 400 gross tonnage and above carry an approved Shipboard Oil Pollution Emergency Plan (SOPEP). Article 3 of the International Convention on Oil Pollution Preparedness, Response and Co-operation, 1990, also requires such a plan for certain ships.
Regulation 17 of MARPOL Annex II makes similar stipulations that all ships of 150 gross tonnage and above carrying noxious liquid substances in bulk carry an approved shipboard marine pollution emergency plan for noxious liquid substances.
The latter may be combined with a SOPEP, since most of their contents are the same and one combined plan on board is more practical than two separate ones in case of an emergency. To make it clear that the plan is a combined one, it should be referred to as a Shipboard Marine Pollution Emergency Plan (SMPEP).
