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).
The purpose of the Plan is to provide guidance to the Master and officers on board the Ship with respect to the steps to be taken when an oil or marine pollution incident has occurred or is likely to occur. The appendices contain communication data of all contacts referenced in the Plan, as well as other reference material.