Updated: 26 October 2026 · 3 min read
IALA (International Organization for Marine Aids to Navigation) sets the common technical framework for lighthouses, buoys, AIS AtoN, VTS and digital navigation services worldwide. Modern AtoN equipment – including Sealite, Sabik and Carmanah products – is designed to meet IALA recommendations.
From association to intergovernmental organisation
- IALA was founded in 1957 and is headquartered in Saint-Germain-en-Laye, France.
- Its members include national AtoN authorities, associate members and industrial members (manufacturers and service providers).
- The Convention on the International Organization for Marine Aids to Navigation entered into force in 2024, turning IALA from a non-governmental association into an intergovernmental organisation, which has since held its first General Assembly.
IALA documents
| Type | Reference | Purpose |
|---|---|---|
| Standards | S1010 – S1070 | Top-level framework for each domain: AtoN planning, VTS, training… |
| Recommendations | R… | What IALA recommends members apply |
| Guidelines | G… | Detailed how-to and technical examples |
| Manuals | NAVGUIDE, VTS Manual… | Consolidated reference |
| Model courses | L1.1, L1.2… | Training for managers and technicians |
Always cite the number and edition of an IALA document in specifications – many were renumbered (e.g. former “A-126” is now “R0126”).
The IALA Maritime Buoyage System (MBS)
Unified in 1980, the MBS divides the world into two regions:
- Region A – Europe, Africa, most of Asia and Oceania, including Vietnam: port-hand marks are red, starboard-hand marks green (following the conventional direction of buoyage, normally from seaward).
- Region B – the Americas, Japan, Korea and the Philippines: the colours are reversed.
The main mark types
| Mark | Colour | Topmark | Light |
|---|---|---|---|
| Lateral – port (Region A) | Red | Red can | Red |
| Lateral – starboard (Region A) | Green | Green cone, point up | Green |
| Cardinal (N, E, S, W) | Black and yellow | Two black cones | White, quick or very quick: N continuous, E 3, S 6 + long, W 9 |
| Isolated danger | Black with red band(s) | Two black spheres | White, group flashing (2) |
| Safe water | Red and white vertical stripes | Red sphere | White isophase, occulting, long flash or Morse “A” |
| Special | Yellow | Yellow X | Yellow |
| Emergency wreck marking | Blue and yellow vertical stripes | Upright yellow cross | Alternating blue and yellow |
Emergency wreck marking is increasingly combined with a virtual AIS AtoN so the warning appears instantly on ECDIS.
Availability targets
| Category | Meaning | Recommended availability |
|---|---|---|
| Category 1 | AtoN of vital navigational significance | 99.8% |
| Category 2 | AtoN of important navigational significance | 99.0% |
| Category 3 | AtoN of necessary navigational significance | 97.0% |
At 99.8% the allowable outage is under 18 hours a year – hard to achieve with vessel patrols alone, which is why remote monitoring has become standard practice.
Phuc Nguyen Marine helps specify lights, buoys and monitoring systems to IALA recommendations for each channel. Talk to our engineers.
References: iala.int; IALA R1001 The IALA Maritime Buoyage System.