Hormuz Transit Information for Tanker Operators

Published: 1 August 2025 · Last updated: 31 October 2026

Tanker vessels — crude oil carriers, petroleum product tankers, and LNG/LPG carriers — account for the majority of commercial traffic through the Strait of Hormuz. The Strait is the transit route for approximately 21 million barrels of oil equivalent per day, representing roughly 20% of total global petroleum liquids consumption. For tanker operators, Hormuz transit is not an occasional event but a routine operational requirement with specific clearance, documentation, insurance, and safety obligations.

Why tankers dominate Hormuz traffic

The Persian Gulf is home to some of the world's largest crude oil producers: Saudi Arabia, Iraq, the UAE, Kuwait, and Iran. Qatar is the world's largest LNG exporter. The Strait of Hormuz is the only maritime exit from the Persian Gulf. Vessels carrying Gulf crude to refineries in Asia, Europe, and North America must pass through the Strait outbound; vessels supplying Gulf ports with imported commodities must pass inbound.

According to the US Energy Information Administration, approximately 18–20 oil tankers transit the Strait per day in each direction. This makes Hormuz the single most important crude oil chokepoint in the world.

VLCC transit considerations

Very Large Crude Carriers (VLCCs, typically 200,000–320,000 DWT) face specific navigational constraints in the Strait. The Traffic Separation Scheme (TSS) establishes inbound and outbound lanes; VLCCs must navigate the narrowest section of the TSS with limited sea room, making passage planning critical. Masters should obtain the latest Notices to Mariners for the area, check current admiralty charts, and allow sufficient time for a daylight passage if the vessel's draught or length warrants it.

Under the HTCA's fee schedule, VLCC-class vessels (over 200,000 DWT) fall into the highest fee tier. Fleet operators routing multiple VLCCs through the Strait may benefit from applying as a fleet (three or more vessels) to receive the 10% fleet discount on the aggregate base fee.

Crude tanker vs. product tanker vs. LNG carrier

Crude tankers carry unrefined petroleum from loading terminals such as Ras Tanura (Saudi Arabia) and Kharg Island (Iran). They are typically the largest vessels transiting the Strait and carry the most significant quantity of cargo by volume. Cargo declaration for crude is relatively straightforward: crude oil, grade, and quantity in metric tonnes.

Product tankers carry refined petroleum products — naphtha, fuel oil, jet fuel, gasoil, and others — both in and out of the Gulf. Product tanker cargoes require more detailed declaration as different products have different IMDG and pollution classifications. Operators should ensure the cargo manifest correctly identifies each product by grade and UN number if applicable.

LNG carriers load at terminals including Qatar's Ras Laffan, the world's largest LNG export facility. LNG is classified as a flammable gas under the IMDG Code and is subject to the IGC Code (International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk). LNG carrier transit clearance applications must include the full gas cargo declaration.

Cargo declaration for hydrocarbon cargoes

All hydrocarbon cargoes — crude, products, and liquefied gases — must be declared in the transit clearance application. The declaration requires:

• Cargo type from the standard dropdown (crude oil, petroleum products, LNG/LPG, chemicals)
• Approximate cargo quantity in metric tonnes
• Dangerous goods declaration if the cargo falls under the IMDG Code (required for most petroleum products; LNG is classified as dangerous cargo)

DWT-based fee tiers for tankers

Tankers are the vessel class most directly affected by the DWT-based fee structure. The full fee schedule shows the current tier rates. As a guide:

• Aframax tankers (80,000–120,000 DWT) fall in Tier 3
• Suezmax tankers (120,000–200,000 DWT) fall in Tier 3 or borderline Tier 4
• VLCC (200,000+ DWT) fall in Tier 4, the highest fee tier
• LNG carriers (typically 70,000–175,000 cbm, approximately 70,000–90,000 DWT) fall in Tier 3

Ship-to-Ship (STS) transfer operations in the approaches

Ship-to-Ship transfer operations — lightering of crude or transferring products between vessels at anchor or underway — are conducted in the Gulf of Oman approach and in anchorages near Fujairah. Vessels participating in an STS operation that will subsequently transit the Strait must each hold individual transit clearance certificates. An STS transfer does not exempt either vessel from the clearance requirement.

War risk insurance for tanker operators

The Gulf is a Joint War Committee (JWC) notifiable or listed area for hull war risk purposes. Tanker operators must give notice to their war risk underwriters before entering the Gulf and ensure that their war risk cover is extended to the specific area. Additional premiums are typically payable per voyage; these can be significant for VLCCs with high insured values.

P&I clubs may also require specific notification for Gulf voyages. Tanker operators with US-sanctioned cargoes or charterers could find their P&I cover voided; screening counterparties before fixture is essential.

UKMTO reporting

The UK Maritime Trade Operations (UKMTO) office in Dubai operates a vessel reporting scheme covering the Gulf of Oman, the Arabian Sea, and adjacent areas. Tanker operators are strongly advised to register with UKMTO and provide position reports throughout the transit zone. UKMTO co-ordinates with Combined Maritime Forces in the region and can assist vessels that report suspicious activity or require assistance.

Best Management Practices (BMP6)

BMP6 (Best Management Practices to Deter Piracy and Enhance Maritime Security) is the industry-standard guidance for vessel security in high-risk areas. Tanker masters and company security officers should review BMP6 recommendations before each Gulf transit, with particular attention to measures for preventing unauthorised boarding, citadel procedures, and communication protocols.