Regulation 37 of Annex I of MARPOL requires that oil tankers of 150 tons gross tonnage or more & all ships of 400 tons gross tonnage or more carry an approved shipboard oil pollution plan (SOPEP). The International Convention on Oil Pollution Preparedness, Response & Co-operation, 1990, also requires such a plan for certain ships. Regulation 17 of Annex II of MARPOL makes similar stipulations for all ships of 150 tons gross tonnage & above carrying noxious liquid substances in bulk: they are required to carry on board an approved marine pollution emergency plan for noxious liquid substances. The latter should be combined with a SOPEP, since most of their contents are the same & the combined plan 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). The Guidelines for the Development of Shipboard Marine Pollution Emergency Plans have been developed by IMO to help Administrations & shipowners meet these requirements. Specimen formats are included. References in this edition have been updated to reflect revised Annexes I (regulation 37) & II (regulation 17) of MARPOL.