SOLAS, Load Lines and COLREG
1The lesson in plain words
SOLAS sets ship safety standards. Load Lines limits loading through minimum freeboard. COLREG sets collision-prevention rules.
SOLAS
The International Convention for the Safety of Life at Sea (SOLAS) 1974 covers passenger ships and cargo ships of 500 gross tonnage (GT, a measure of enclosed volume) or more on international voyages, with chapter-specific exceptions. Chapters cover construction (II-1), fire (II-2), life-saving appliances (III), radio (IV), navigation (V), cargoes (VI), dangerous goods (VII), nuclear ships (VIII), safety management (IX), high-speed craft (X), special safety measures (XI-1), security (XI-2), bulk carriers (XII), verification of compliance (XIII), polar waters (XIV) and industrial personnel (XV).
Codes made mandatory
SOLAS makes detailed codes mandatory: the Fire Safety Systems (FSS) Code, Life-Saving Appliances (LSA) Code, International Maritime Dangerous Goods (IMDG) Code and International Maritime Solid Bulk Cargoes (IMSBC) Code. Chapter IX makes the International Safety Management (ISM) Code mandatory; XI-2 does the same for the International Ship and Port Facility Security (ISPS) Code. Chapter IV radio rules also cover cargo ships from 300 GT. Parts of chapter V, including voyage planning and helping people in distress, apply even to yachts.
Recent SOLAS changes
From 1 January 2026, SOLAS II-1/3-13 covers lifting appliances and anchor-handling winches. Covered new installations meet design standards; covered existing equipment needs testing and examination by the first renewal survey on or after that date. PFOS, a persistent fluorinated chemical, is prohibited in fire-extinguishing media; existing ships comply by their first survey on or after that date. Masters promptly report lost containers to nearby ships, the nearest coastal state and the flag, and report drifting containers they see.
Autonomous ships
In May 2026 MSC 111 adopted the Maritime Autonomous Surface Ships (MASS) Code. It is voluntary from 1 July 2026. A mandatory version is planned for 2032.
Load Lines
The Load Lines Convention 1966, updated by its 1988 Protocol, sets minimum freeboard: the vertical distance amidships (at mid-length) from the deck line’s upper edge to the applicable load line’s upper edge. The ship carries an International Load Line Certificate. Marks identify S (summer), T (tropical), W (winter), F (fresh water), TF (tropical fresh water) and WNA (winter North Atlantic). Select the applicable mark for the zone, season and water density; its upper edge is the loading limit. Freeboard provides reserve buoyancy and reduces water washing over the deck.
COLREG
The Convention on the International Regulations for Preventing Collisions at Sea (COLREG) 1972 entered into force in 1977. It applies to all vessels on the high seas and connected waters navigable by seagoing vessels. Appropriate authorities may make special rules for roadsteads, harbours, rivers, lakes and connected inland waters navigable by seagoing vessels. These must conform as closely as possible to COLREG. Study the Rules in the COLREG module.
2Key data
- SOLAS 1974
- In force 25 May 1980; cargo ships of 500 GT+ on international voyages
- PFOS transition
- 2026 PFOS ban: existing ships comply at first survey on/after 1 Jan
- MASS Code
- Adopted May 2026; voluntary from 1 July 2026
- Load Lines
- 1966 Convention; 1988 Protocol in force 3 Feb 2000
- COLREG 1972
- In force 15 July 1977; includes connected seagoing-navigable waters
3Key points
- 1
SOLAS covers construction, fire, LSA, radio, navigation, cargo, ISM and ISPS.
- 2
Mandatory codes such as FSS, LSA, IMDG and IMSBC carry most of the detail.
- 3
Since 1 January 2026 you must report lost freight containers at once.
- 4
Load Lines set the minimum freeboard; COLREG applies to every vessel at sea.
4Frequent mistakes
Wrong: SOLAS has nothing to say to a yacht.
Right: Most of SOLAS does not apply, but parts of chapter V, such as voyage planning and distress duties, bind all ships.
Wrong: The MASS Code is now mandatory for autonomous ships.
Right: The code adopted in 2026 is voluntary. A mandatory version is planned for about 2032.
Wrong: A coastal state can replace COLREG with its own rules anywhere off its coast.
Right: Appropriate authorities may make special rules for roadsteads, harbours, rivers, lakes and connected inland waters navigable by seagoing vessels. These must conform as closely as possible to COLREG.
5Practice case & exam keys
In heavy weather your container ship loses six containers overboard at night, 40 NM off a coast. The chief mate wants to wait until daylight to count the losses before reporting. What does SOLAS now require?
Show the answer
Report at once, without waiting for an exact count. Since 1 January 2026, SOLAS chapter V requires you to inform ships nearby, the nearest coastal state and the flag state. Give the position, the number lost, and any dangerous goods. Send updates as you learn more. Drifting containers are a danger to navigation, especially for small craft at night.
Exam keys
- SOLAS 1974: chapters II-1 to XV; codes FSS, LSA, IMDG, IMSBC made mandatory.
- 1 January 2026: lifting appliances II-1/3-13, PFOS ban with existing-ship survey transition, lost-container reporting.
- Load Lines 1966/1988: freeboard, marks, zones, International Load Line Certificate.
- COLREG 1972: in force 1977, applies to all vessels at sea.
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