What STCW certificate is required to be a Cargo Officer on an LNG carrier?

Officers with immediate cargo responsibility on an LNG or LPG carrier require the Advanced Liquefied Gas Tanker Operations endorsement under STCW A-V/1-2-2. This is in addition to the Basic LG endorsement (STCW A-V/1-2-1), which is the minimum for any seafarer performing cargo duties on a gas carrier. The Advanced LG endorsement must be refreshed every five years. Most LNG operators additionally require company-specific LNG familiarisation training and a supervised sea period before the officer takes cargo responsibility.

What is BOG and why is it important on LNG carriers?

Boil-off gas (BOG) is the natural vapourisation of LNG cargo as heat permeates the insulation of the cargo tanks. On modern LNG carriers, BOG is managed in several ways: reliquefaction (compressing and cooling BOG back to liquid), use as propulsion fuel in dual-fuel diesel engines or steam turbines, or venting in approved circumstances. Cargo officers must understand the cargo conditioning process — maintaining cargo temperature and pressure within the cargo tanks to prevent over-pressure or cargo degradation — and must log BOG rates as part of custody transfer calculations.

What is the LNG Cargo Officer (LCO) role?

The LNG Cargo Officer (LCO) is a specialist cargo management role on large LNG carriers, distinct from the standard navigational OOW role. LCOs are responsible for all aspects of cargo operations: loading, discharging, heel management, cool-down and warm-up procedures, BOG management, custody transfer measurement (CTM), and cargo documentation. Many major LNG operators require the LCO to hold both the STCW Advanced LG endorsement and a company-specific LCO qualification. Some operators offer dedicated LCO career tracks that do not require the full deck-officer CoC — though a watchkeeping certificate is typically a prerequisite.

Why are LNG/LPG officer salaries the highest in commercial shipping?

LNG/LPG carriers combine the hazard premium of gas cargo (cryogenic temperatures, flammability, BLEVE risk) with the complexity of modern cargo containment systems (membrane, MOSS spherical, type C), high capital asset values (a modern QFLEX LNG carrier costs over USD 200 million), and stringent charterer vetting. Officers with Advanced LG endorsements and LNG operational experience are in short supply relative to the rapid fleet expansion driven by the global energy transition. Master and Chief Engineer wages on large LNG carriers regularly exceed USD 18,000–22,000/month.

Who is SIGTTO and what training do they offer?

SIGTTO (Society of International Gas Tanker and Terminal Operators) is the industry association for gas tanker and terminal operators. SIGTTO publishes best-practice guidance (the Liquefied Gas Handling Principles on Ships and in Terminals — LGHP4), provides a liquid cargo officer competency framework, and accredits LNG/LPG training courses at member training centres. Completion of a SIGTTO-endorsed course is recognised by many major LNG operators as part of the qualification pathway for LCO and cargo-officer roles.

LNG and LPG careers — liquefied gas tanker specialist track

Liquefied natural gas (LNG) and liquefied petroleum gas (LPG) carriers represent the most technically complex and highest-paying sector in commercial shipping. Officers on these vessels operate cryogenic cargo systems, manage boil-off gas (BOG), interface with custody transfer metering, and navigate the IGC Code compliance requirements — all in addition to the standard navigational and engineering duties of a commercial officer. The global LNG fleet is growing rapidly as energy importers invest in regasification infrastructure; demand for Advanced LG-endorsed officers and LNG Cargo Officers significantly outpaces supply. STCW sets the international floor; the issuing flag state can add national requirements — always verify with the issuing administration. See also the broader tanker careers page and the career pathways reference.

STCW endorsements — gas carriers

Basic Training for Liquefied Gas Tanker Cargo Operations (STCW A-V/1-2-1) — Minimum requirement for any seafarer with designated cargo duties on a gas carrier (LNG, LPG, ethylene, ammonia). Covers cargo properties, IGC Code overview, cargo containment systems, basic operations, and emergency procedures. Prerequisite for the Advanced LG endorsement.
Advanced Liquefied Gas Tanker Operations (STCW A-V/1-2-2) — Required of officers with immediate cargo responsibility on a gas carrier. Covers cargo containment systems (membrane, MOSS spherical, type C/independent), cargo handling design, BOG management, custody transfer, IGC Code compliance, emergency shutdown systems, and secondary barrier integrity. Refresher every 5 years.

Key technical areas — LNG operations

Cargo containment systems — Membrane (GTT No.96 and Mark III, most common on modern vessels), MOSS spherical (Kvaerner), and type C independent tanks (most LPG carriers). Each has different insulation, secondary barrier, and operational characteristics.
Cargo conditioning and cool-down — Before loading LNG, tanks must be inerted and cooled down progressively using LNG spray; a poorly managed cool-down risks cargo tank damage. Warm-up after discharging requires controlled heating procedures to maintain tank integrity.
BOG management — Boil-off gas is managed via reliquefaction plant, dual-fuel engines, or gas combustion units (GCU). Cargo officers log and report BOG rates as part of custody transfer and voyage reporting.
Custody transfer measurement (CTM) — LNG cargo quantity is measured by tank gauging (level measurement), temperature sensors, pressure gauges, and density calculation. CTM accuracy is critical as LNG is sold by energy content (MMBtu). Cargo officers produce NOR (Notice of Readiness), BDN (Bunker Delivery Note equivalent), and cargo calculation reports.
High Voltage (HV) systems — Modern LNG carriers with dual-fuel diesel electric propulsion or steam turbines operate HV power systems. ETOs and engineers require the High Voltage Safety endorsement. Reliquefaction compressors also typically operate on HV circuits.

LNG Cargo Officer (LCO) progression

The LCO role is the specialist cargo-management position unique to LNG carriers. Progression typically runs:

· Junior LCO / Third Officer LCO: Holds Advanced LG endorsement; supervised cargo operations under the Chief Officer LCO or Cargo Superintendent. Some operators hire junior LCOs directly from gas-tanker deck officers.
· Senior LCO / Chief Officer LCO: Full cargo responsibility; interfaces directly with terminal operators and ship chandler for CTM; produces all cargo documentation.
· Master / Staff Captain with LCO background: The progression to Master on LNG carriers normally requires both a Master CoC and significant LCO operational experience.

SIGTTO training centres

SIGTTO-accredited and endorsed LNG/LPG training is available at specialist maritime training centres including: Kongsberg Maritime (Norway), LOGT (Netherlands), Warsash Maritime School (UK), FKAB Marine Engineering (Sweden), Chinese Maritime Research Institute (CMRI), and the LNG Academy Manila (Philippines). Verify that the course is approved by the issuing flag state and accepted by the operator's vetting standards before booking.

Salary ranges (2025)

LNG and LPG carrier officers earn the highest wages in commercial shipping outside luxury superyachts. Indicative monthly rates for LNG carriers:

· OOW / LCO (junior): USD 5,500–7,500/month
· Chief Mate / Senior LCO: USD 9,000–13,000/month
· Master: USD 14,000–22,000/month
· Chief Engineer: USD 13,000–20,000/month
· LPG carriers command slightly lower rates (USD 10–15% below LNG equivalents).

Full data by vessel type in the salary database.

Frequently asked questions

What STCW certificate is required to be a Cargo Officer on an LNG carrier?
Officers with immediate cargo responsibility on an LNG or LPG carrier require the Advanced Liquefied Gas Tanker Operations endorsement under STCW A-V/1-2-2. This is in addition to the Basic LG endorsement (STCW A-V/1-2-1), which is the minimum for any seafarer performing cargo duties on a gas carrier. The Advanced LG endorsement must be refreshed every five years. Most LNG operators additionally require company-specific LNG familiarisation training and a supervised sea period before the officer takes cargo responsibility.
What is BOG and why is it important on LNG carriers?
Boil-off gas (BOG) is the natural vapourisation of LNG cargo as heat permeates the insulation of the cargo tanks. On modern LNG carriers, BOG is managed in several ways: reliquefaction (compressing and cooling BOG back to liquid), use as propulsion fuel in dual-fuel diesel engines or steam turbines, or venting in approved circumstances. Cargo officers must understand the cargo conditioning process — maintaining cargo temperature and pressure within the cargo tanks to prevent over-pressure or cargo degradation — and must log BOG rates as part of custody transfer calculations.
What is the LNG Cargo Officer (LCO) role?
The LNG Cargo Officer (LCO) is a specialist cargo management role on large LNG carriers, distinct from the standard navigational OOW role. LCOs are responsible for all aspects of cargo operations: loading, discharging, heel management, cool-down and warm-up procedures, BOG management, custody transfer measurement (CTM), and cargo documentation. Many major LNG operators require the LCO to hold both the STCW Advanced LG endorsement and a company-specific LCO qualification. Some operators offer dedicated LCO career tracks that do not require the full deck-officer CoC — though a watchkeeping certificate is typically a prerequisite.
Why are LNG/LPG officer salaries the highest in commercial shipping?
LNG/LPG carriers combine the hazard premium of gas cargo (cryogenic temperatures, flammability, BLEVE risk) with the complexity of modern cargo containment systems (membrane, MOSS spherical, type C), high capital asset values (a modern QFLEX LNG carrier costs over USD 200 million), and stringent charterer vetting. Officers with Advanced LG endorsements and LNG operational experience are in short supply relative to the rapid fleet expansion driven by the global energy transition. Master and Chief Engineer wages on large LNG carriers regularly exceed USD 18,000–22,000/month.
Who is SIGTTO and what training do they offer?
SIGTTO (Society of International Gas Tanker and Terminal Operators) is the industry association for gas tanker and terminal operators. SIGTTO publishes best-practice guidance (the Liquefied Gas Handling Principles on Ships and in Terminals — LGHP4), provides a liquid cargo officer competency framework, and accredits LNG/LPG training courses at member training centres. Completion of a SIGTTO-endorsed course is recognised by many major LNG operators as part of the qualification pathway for LCO and cargo-officer roles.

Primary sources

Flag-state caveat: STCW sets the international floor. Individual flag administrations may require additional national examinations, additional gas-carrier familiarisation requirements, or supplementary courses beyond those listed here. Always verify current requirements with the issuing flag-state administration.

This page is for information only and does not constitute legal or professional advice. Requirements change — verify with the relevant authorities before acting.