The Panama Maritime Authority (PMA), through adopted circular MMC-217, has introduced stricter requirements for ship-to-ship (STS) transfers of oil cargo. The circular supports measures to prevent illegal “dark fleet” or “shadow fleet” operations in the maritime sector.

From 6 August 2025, Panama flagged oil tankers of 150gt and above, acting as a discharging or/and receiving vessel, must:

• Update their STS operations plan to include “Transfer Notification” information as specified in MMC-217 paragraph 6.6.
• Transmit the required information to the Panama Flag Administration through the E-Segumar Platform at least 48 hours prior to the planned STS transfer operations. The new E-Segumar module will be online from 6 August 2025.
• Comply with these requirements for timely notification or face possible administrative measures (as per maritime regulations and oversight procedures established by the Administration).

IMO requirements

The new STS controls of PMA circular MMC-217 are intended to support the “shadow fleet” preventative measures of IMO Resolution A.1192(33) and are additional to the following existing IMO legislation:

• MARPOL Annex I, Chapter 8: this requires tankers to carry out STS transfers of oil cargo in accordance with an approved STS operations plan.
• MARPOL Annex I, Regulation 42: this requires the Coastal Flag State to be notified where STS operations are planned in the territorial sea, or the exclusive economic zone of that Flag State (where the Flag State is a party to the MARPOL Convention).​​​​

What should shipowners and ship operators do now?

The updated STS operations plan must be ready on board and presented to the surveyor for verification during the first annual, intermediate or renewal survey of the International Oil Pollution Prevention Certificate (IOPP), whichever occurs first, after 6 August 2025.