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MARPOL Annex I Ch. 8 · IMO Res. A.1192(33) · OCIMF/ICS STS Guide · SOPEP / SMPEP

Ship-to-Ship (STS) Transfer Plan, 48-Hour Notice & SOPEP Spill Checklist

Ship-to-Ship (STS) cargo transfers and SOPEP / SMPEP pollution-response readiness are among the highest-consequence inspection areas in SIRE 2.0 Chapter 5 & Chapter 8, Port State Control, and Flag State audits — especially following the adoption of IMO Resolution A.1192(33) targeting sanction-evading "dark fleet" STS transfers and AIS manipulation.

Complementing our ISGOTT 6 Ship/Shore Safety Checklist Guide and Bunkering & Fuel Changeover Checklist, this guide covers MARPOL Annex I Chapter 8 (`Regs. 40–42`), the OCIMF/ICS/SIGTTO/CDI STS Checklists 1–5, POAC qualifications, primary/secondary fender and hose rigging, and SOPEP / SMPEP equipment and contact-list verification.

Updated · Written by SeaReady in our own words. Not affiliated with OCIMF, RightShip, CDI, any MoU or any administration — always check the current official documents.

1. MARPOL Annex I Chapter 8, IMO Res. A.1192(33) & SOPEP Regulatory Summary

Every Master, Chief Officer, and Chief Engineer on a tanker or merchant vessel must ensure strict compliance across five statutory and industry frameworks governing STS transfers and oil spill response:

MARPOL Annex I Ch. 8 (Regs. 40–42), IMO Res. A.1192(33), OCIMF/ICS STS Guide and SOPEP/SMPEP requirements.
Requirement & RegulationApplicability & ThresholdStatutory & Vetting Standard
Approved STS Operations Plan (MARPOL Annex I Ch. 8 Reg. 41)Mandatory for oil tankers ≥ 150 GT engaged in STS oil cargo transfersApproved by the Flag Administration (placed on board no later than the first survey after 1 January 2011) and written in the working language of the ship, incorporating the IMO Manual on Oil Pollution Section I and the OCIMF/ICS/SIGTTO/CDI Ship-to-Ship Transfer Guide.
48-Hour Coastal & Flag State Notification (MARPOL Annex I Reg. 42 & IMO Res. A.1192(33))Not less than 48 hours prior to scheduled STS oil transfer in territorial sea or EEZThe tanker must notify the coastal State ≥ 48 hours ahead (name, flag, call sign, IMO number, estimated time/location of commencement, oil type/quantity, duration, and STS service provider / POAC contact). Under IMO Resolution A.1192(33) (6 Dec 2023), Flag States also require notification of mid-ocean STS transfers and continuous AIS/LRIT transmission.
Person in Overall Advisory Control — POAC (MARPOL Annex I Reg. 41.4)STCW Management-Level Deck CoC + Oil Tanker Endorsement + STS TrainingThe individual in overall advisory control of the STS operation must be qualified across all management-level STCW cargo-handling and pollution-prevention competencies; on board each ship, the Master retains ultimate command and overriding responsibility for the safety of their own vessel.
STS Checklists 1 to 5 & Record Retention (CDI/ICS/OCIMF/SIGTTO STS Transfer Guide, 2nd ed. Oct 2025)Checklists 1–5 completed sequentially; retained on board for ≥ 3 yearsChecklist 1 (Pre-Fixture Information), Checklist 2 (Before Operations Commence), Checklist 3 (Before Run-In & Mooring), Checklist 4 (Before Cargo Transfer Commences, plus ISGOTT Ship/Ship Safety Checklist), and Checklist 5 (Before Unmooring) must be signed and kept with the Oil Record Book Part II for 3 years (Reg. 41.5).
SOPEP & SMPEP Shipboard Oil/Marine Pollution Emergency Plan (MARPOL Annex I Reg. 37 & Annex II Reg. 17)Mandatory for oil tankers ≥ 150 GT & all other ships ≥ 400 GTClass/Flag-approved emergency plan containing the reporting procedures (IMO Res. A.851(20) POLREP), current Q1–Q4 2026 IMO MEPC.6/Circ Coastal State Focal Point List, Company DPA/QI 24/7 emergency contacts, tank/piping general arrangement plans, and deck spill containment procedure.

2. OCIMF / ICS STS Checklists 1 to 5, Fenders & Cargo Hoses

Under the joint CDI / ICS / OCIMF / SIGTTO Ship to Ship Transfer Guide for Petroleum, Chemicals and Liquefied Gases (2nd edition, published 21 Oct 2025, replacing the 2013 edition) and the vessel’s approved STS Operations Plan, every transfer progresses through five checklists. The checklist names below follow the 2013 edition — check them against the 2nd edition held on board:

  • Checklist 1 (Pre-Fixture Information) & Compatibility Assessment: Completed before fixture confirmation — verifies vessel dimensions, freeboard/manifold height differences, mooring arrangement compatibility (OCIMF MEG4 fairleads and SWL), parallel mid-body length, and STS service provider vetting.
  • Checklist 2 (Before Operations Commence) & Primary/Secondary Fenders: Verifies weather and swell limits, VDR/AIS status, continuous VHF communication, and valid pressure-test certificates for primary pneumatic fenders (ISO 17357 safety relief valves tested) and secondary foam/baby fenders rigged at bow and stern quarters.
  • Checklist 3 (Before Run-In & Mooring) & Manoeuvring Approach: Confirms engine/steering gear readiness, anchor readiness on the off-side, navigation warning broadcasts, and whether the transfer will be conducted at anchor or underway (drifting / making way) under the advice of the POAC.
  • Checklist 4 (Before Cargo Transfer) & Checklist 5 (Before Unmooring): Completed alongside the ISGOTT 6 Ship/Ship Safety Checklist — verifies EN 1765 / BS 1435 cargo hose annual pressure test and continuity/insulation certificates, manifold support saddles, inert gas (< 8% O₂ and positive pressure), agreed transfer rates/pressures, ESD test, and safe hose draining/purging/blanking before cast-off.

3. SOPEP / SMPEP Locker, Scupper Plugs & USCG VRP Inspection Readiness

Whether conducting a full cargo STS transfer or routine fuel oil bunkering, Port State Control and SIRE 2.0 inspectors inspect four physical and documentary elements of the vessel’s SOPEP / SMPEP and USCG Vessel Response Plan (VRP):

Physical and documentary SOPEP, SMPEP and USCG VRP checkpoints inspected during PSC and SIRE 2.0.
Inspection AreaMandatory StandardShipboard Verification Checklist
Deck Scupper Plugs & Manifold Savealls100% plugged & tight before any bunker or STS transferInsert mechanical rubber expandable scupper plugs (and cement/wooden plugs where applicable) along the entire main deck, drain manifold drip trays before transfer, and keep portable pneumatic wilden pumps primed at the aft manifold / deck break.
SOPEP Locker Inventory & Absorbent ReadinessInventoried monthly against approved SOPEP equipment listVerify absorbent pads, booms, pillows, sawdust/peat moss, non-sparking shovels/scoops, portable air-driven transfer pump + grounding cable, chemical-resistant gloves/boots/goggles, and labelled hazardous-waste disposal drums.
USCG VRP / NTVRP Qualified Individual (QI) & SMFF33 CFR Part 155 — US waters mandatory notification within 30 minWhen operating in US waters, bridge and engine officers must know the named Qualified Individual (QI), OSRO, and Salvage & Marine Firefighting (SMFF) provider in the USCG Vessel Response Plan (VRP) and conduct quarterly QI notification exercises.
Emergency Shutdown (ESD) & Hose Pressure TestingTested before every STS / bunker transfer and loggedVerify agreed emergency stop signals (pneumatic/fibre-optic/electric ESD link or VHF channel + horn blast), confirm cargo/bunker hose hydrostatic test certificates (within 12 months), and check insulating flanges or electrical continuity bonding per ISGOTT 6.

4. Preventing Illegal 'Dark Fleet' STS Exposure Under IMO Res. A.1192(33)

Adopted on 6 December 2023, IMO Assembly Resolution A.1192(33) directs Port States, Flag States, and maritime service providers to apply enhanced due diligence to Ship-to-Ship operations:

  • Continuous AIS & LRIT Transmission (`SOLAS V/19.2.4 & V/19-1`): Never switch off or attenuate AIS or LRIT during or prior to an STS operation unless an imminent physical security threat (such as piracy) requires it — in which case the Master must immediately log the exact time, position, and reason in the Official/Deck Log Book and notify the Flag State and coastal authority.
  • Sanctions, P&I & Bill of Lading Provenance Screening: Before accepting an STS nomination, verify the counterpart tanker’s IMO number, current International Group P&I Club entry (`Standard A2.5.2` / `CLC 1992` Blue Card), valid Class status, and authentic cargo origin documentation.
  • Synchronised Oil Record Book Part II (Code G / Code H) & STS Plan Filing: Ensure the exact UTC start/stop times, lat/long positions, counter-vessel IMO number, and metric tons/cubic metres transferred in Oil Record Book Part II match the Deck Log Book, Ullage Report, and signed STS Checklists 1–5 retained for 3 years.

Questions seafarers ask

Which vessels are required to carry an approved STS Operations Plan under MARPOL Annex I Chapter 8?

Under MARPOL Annex I Chapter 8 Regulation 41, every oil tanker of 150 gross tonnage and above engaged in the transfer of oil cargo between oil tankers at sea (Ship-to-Ship or STS operations) must carry on board an STS Operations Plan approved by its Flag Administration. Note that bunkering operations, FPSO/FSU offloading, and transfers at fixed/floating offshore platforms are excluded from Chapter 8, though they remain governed by the ship’s SMS, SOPEP, and bunker/terminal checklists.

What is the 48-hour STS advance notification requirement under MARPOL Annex I Regulation 42 and IMO Resolution A.1192(33)?

Under MARPOL Annex I Regulation 42, each oil tanker subject to Chapter 8 that plans to carry out an STS operation within the territorial sea or Exclusive Economic Zone (EEZ) of a Party to MARPOL must notify that coastal State not less than 48 hours in advance of the scheduled STS operation. Furthermore, IMO Assembly Resolution A.1192(33) (adopted 6 December 2023 to combat illegal "dark fleet" operations) urges Flag States to require vessels to adhere to the spirit of the 48-hour STS notification regime, notify their Flag Administration when conducting mid-ocean STS transfers, and prohibit unexplained AIS or LRIT switch-offs.

How long must STS Operations Plan records and checklists be retained on board?

Under MARPOL Annex I Regulation 41.5, records of all STS operations — including the completed STS Checklists 1 to 5, weather/fender/hose verifications, and Oil Record Book Part II entries — must be retained on board for three (3) years and be readily available for inspection by Port State Control and Flag State surveyors.

What is the single most common SOPEP deficiency recorded during Port State Control inspections?

The most frequent SOPEP deficiency is an outdated Annex 2 List of National Operational Contact Points (IMO Circular MEPC.6/Circ series, updated quarterly on the IMO website) or missing/expired 24-hour Company DPA and USCG Qualified Individual (QI) contact numbers, followed by corroded or unprimed pneumatic spill-recovery pumps and missing non-sparking tools inside the deck SOPEP locker.

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