As adopted by the resolution MEPC.186(59), a  new chapter 8 to the MARPOL Annex I is introduced and Regulations 40,41 and 42 included,  state that all oil tankers of 150 Gross Tonnage and above engaged in the transfer of oil cargo between oil tankers at sea (STS Operation) conducted on or after 1 April 2012,  are required to have onboard and should implement an STS Operation plan approved by the Administration.
Since these new Regulations under MARPOL ANNEX I will enter into force on  1 January 2011, Streamlined Naval Architects have already developed an easy-to-use STS Operations plan, in accordance to the information contained in the IMO “Manual on Oil Pollution, Section 1 Prevention” as amended, and the ICS and OCIMF “Ship to Ship Transfer Guide, Petroleum, fourth edition, 2005”.
In detail, as quoted from Regulation 41 :
MARPOL ANNEX I, Chapter 8, Regulation 41
General Rules on safety and environmental protection
1. Any oil tanker involved in STS operations shall carry on board a Plan prescribing how to conduct STS operations (STS operations Plan) not later than the date of the first annual, intermediate or renewal survey of the ship to be carried out on or after 1 January 2011. Each oil tanker’s STS operations Plan shall be approved by the Administration. The STS operations Plan shall be written in the working language of the ship.
2. The STS operations Plan shall be developed taking into account the information contained in the best practice guidelines for STS operations identified by the Organization. The STS operations Plan may be incorporated into an existing Safety Management System required by chapter IX of the International Convention for the Safety of Life at Sea, 1974, as amended, if that requirement is applicable to the oil tanker in question.
3. Any oil tanker subject to this chapter and engaged in STS operations shall comply with its STS operations Plan.
4. The person in overall advisory control of STS operations shall be qualified to perform all relevant duties, taking into account the qualifications contained in the best practice guidelines for STS operations identified by the Organization.
5. Records of STS operations shall be retained on board for three years and be readily available for inspection by a Party to the present Convention.