What are the sulphur limits, non-availability actions, BDN mismatch handling and in-use sampling point timelines under MARPOL?

flowchart TD
    A[Global limit 0.50% m/m] --> B[ECA limit 0.10% m/m]
    C[Cannot obtain compliant fuel] --> D[Notify Admin + port]
    D --> E[Record attempts]
    F[Commercial analysis ≠ BDN] --> G[Supplier responsible]
    H[Sampling points] --> I[New ships: at build]
    H --> J[Existing ships: first renewal survey ≥1 Apr 2023]

• Global sulphur limit: 0.50% m/m (MARPOL Annex VI Reg 14.1)
• ECA sulphur limit: 0.10% m/m (MARPOL Annex VI Reg 14.4)
• Non-availability action: notify Administration and port of destination, record attempts to purchase compliant fuel, no deviation/delay required (MARPOL Annex VI Reg 18.2)
• BDN mismatch: ship not blamed if fuel received in good faith; supplier responsible (BMA Bulletin 75 §6.1)
• In-use sampling points: fitted/designated for all ships; for ships built before 1 Apr 2022, not later than first renewal survey on/after 1 Apr 2023 (MARPOL Annex VI Reg 14.10–14.11)
• Applies to existing ships: yes, via first renewal survey after 1 Apr 2023