Electronic Navigational Charts (ENC)
IHO S-57 standard ENCs for ECDIS — vector format charts with attribution data for navigational safety systems. Required for SOLAS vessels fitted with type-approved ECDIS.
Global ENC Cells
40,000+
IHO Standard
S-57 / S-101
Update Frequency
Weekly
SOLAS Requirement
ECDIS mandatory
ENC Distribution Services
AVCS (Admiralty Vector Chart Service)
Largest single ENC service — distributed through licensed chart agents
IC-ENC
International Chart ENC service — data from 30+ national hydrographic offices
PRIMAR
Norwegian-led distributor covering Scandinavia, Baltic, North Sea
ENC Direct
Direct purchase from national hydrographic offices (e.g., NOAA, AHS, HO Korea)
ENC Usage Bands (Scale / Purpose)
| Band | Scale Range | Purpose |
|---|---|---|
| Usage Band 1 | > 1:1,500,000 | Overview |
| Usage Band 2 | 1:350,000 – 1:1,500,000 | General |
| Usage Band 3 | 1:90,000 – 1:350,000 | Coastal |
| Usage Band 4 | 1:22,000 – 1:90,000 | Approach |
| Usage Band 5 | 1:4,000 – 1:22,000 | Harbour |
| Usage Band 6 | < 1:4,000 | Berthing |
Priceband Reference
Small scale overview charts — ocean passage planning (1:3.5M+)
General coastal charts — passage and approach planning
Coastal/harbour approach charts — port entries and anchorages
Harbour and berthing charts — detailed port areas
Very large scale harbour charts — most detailed coverage
Specialised or complex port areas — high-detail harbour plans
S-57 vs S-101
IHO S-57 (Current)
Existing ENC standard — all current ECDIS and ENCs are S-57 compliant. Will remain in use alongside S-101 during transition.
IHO S-101 (Next Generation)
New standard with richer data attributes, better theming, and support for e-navigation services. Production ENCs being issued from 2025.