How often should ECDIS charts be updated?

At every available opportunity but at minimum weekly under SOLAS V Reg. 19.2.1.4 and IMO Resolution A.817(19). Hydrographic Offices publish weekly Notice to Mariners and ENC update batches; chart distributors push these on subscription. PSC inspectors check the 'last update' date on the ENCs covering the planned route and the current passage.

IHO Standard S-63 — Data Protection Scheme for ENCs. It encrypts the chart cells, ties decryption to the specific ECDIS user permit (a hardware-bound key), and prevents redistribution. Update files are signed and verified on import; tampered files are rejected. Without S-63 access, the ECDIS displays only the base IHO chart catalogue without nautical content.

IHO Standard S-58 — Validation Checks for ENC. It is a quality-assurance suite of automated tests (currently 200+ checks) that producers run before publication. Issues like overlapping geometries, missing depth contour, or incorrect attribute combinations are flagged and corrected. The standard does not affect the user side directly but is why modern ENCs are higher quality than the early 2000s issues.

Next-generation IHO ENC product specification, replacing S-57 over a multi-year transition. S-101 supports richer attribution (e.g. dynamic UKC, dynamic sea-state overlay), portrayal rules separated from the data, and harmonised data-quality indicators. ECDIS manufacturers are rolling out dual-fuel ECDIS that handle both S-57 and S-101 data simultaneously during the transition window.

Admiralty Information Overlay — a UKHO product that overlays Temporary and Preliminary (T&P) notices, plus 'Useful information', on ENCs. Available to ENC subscribers; routinely turned on during passage planning to spot recently-published changes that may not yet be in the base ENC. Other HOs offer equivalent overlays.

Electronic chart updates

ECDIS-equipped ships under SOLAS V Reg. 19.2.10 must keep ENCs corrected to the latest available update before sailing and during voyage. The chart-update workflow runs on top of three IHO standards — S-63 (data protection), S-58 (quality validation), and S-101 (next-generation product) — plus the publishing weekly Notice to Mariners and Admiralty Information Overlay (UKHO).

The update cycle

Base CD / DVD — issued every ~3 months, contains the full ENC catalogue at that issue date. Loaded into the ECDIS as the new starting point.
Update CD / DVD — issued weekly, contains incremental ENC update files for cells that have changed since the last base. Cumulative; the ECDIS applies them in sequence.
Online weekly update — most ships now download the same update files via VSAT or Fleet Xpress; many distributors offer a single .zip per week.
T&P notices (Temporary & Preliminary) — UKHO via the AIO overlay; many other HOs publish their T&P as separate downloadable files. ECDIS displays them as a layer above the base ENC.
Navigational warnings — broadcast by NAVTEX (Sea Area A1/A2) and SafetyNET (A3/A4); the OOW logs them and updates passage planning live.

S-63 in detail

· ENC files are encrypted and signed by the producing Hydrographic Office.
· The user permit ties decryption to a specific ECDIS unit (hardware-bound). Each ECDIS has its own user permit.
· To switch ECDIS units (e.g. on changeover), the operator obtains a new permit from the chart distributor and reloads cells.
· Updates are signed; tampered or partial updates are rejected by the ECDIS — preventing route plans being drawn on out-of-date or unverified data.

Crew workflow

· Daily — OOW reviews navigational warnings (NAVTEX, SafetyNET) and updates passage plan as needed.
· Weekly — ETO or Chief Mate downloads or installs ENC update batch; verifies all cells along the planned route are at the current ETRS week.
· Pre-departure — passage plan reviewed against current ENCs and AIO/T&P overlay; chart adequacy confirmed; ECDIS test routine logged.
· Annual — ECDIS performance test, alarm test, route-checking test per IMO Resolution MSC.232(82) Annex 4.
· 5-yearly — ECDIS hardware and ENC subscriptions reviewed at vessel renewal class survey.

PSC and vetting findings

· ENCs not up to date — most-common ECDIS deficiency under Paris MoU CICs.
· Type-specific ECDIS training missing for the model fitted (MSC.1/Circ.1503/Rev.1).
· Backup arrangements not in place (independent ECDIS, paper charts, or appropriate folio).
· Dummy 'route' file from training mode not deleted.
· T&P / AIO overlay not loaded; navigational warnings not transferred to the passage plan.

Sources: SOLAS Chapter V Reg. 19; IMO Resolution A.817(19) (Performance standards for ECDIS); IMO Resolution MSC.232(82) (Revised PS for ECDIS); MSC.1/Circ.1503/Rev.1 (ECDIS familiarisation and type-specific training); IHO S-63 + S-58 + S-101. See also ECDIS overview, passage planning, ECDIS glossary.

Electronic chart updates

The update cycle

Base CD / DVD — issued every ~3 months, contains the full ENC catalogue at that issue date. Loaded into the ECDIS as the new starting point.

Update CD / DVD — issued weekly, contains incremental ENC update files for cells that have changed since the last base. Cumulative; the ECDIS applies them in sequence.

Online weekly update — most ships now download the same update files via VSAT or Fleet Xpress; many distributors offer a single .zip per week.

T&P notices (Temporary & Preliminary) — UKHO via the AIO overlay; many other HOs publish their T&P as separate downloadable files. ECDIS displays them as a layer above the base ENC.

Navigational warnings — broadcast by NAVTEX (Sea Area A1/A2) and SafetyNET (A3/A4); the OOW logs them and updates passage planning live.

S-63 in detail

· ENC files are encrypted and signed by the producing Hydrographic Office.

· The user permit ties decryption to a specific ECDIS unit (hardware-bound). Each ECDIS has its own user permit.

· To switch ECDIS units (e.g. on changeover), the operator obtains a new permit from the chart distributor and reloads cells.

· Updates are signed; tampered or partial updates are rejected by the ECDIS — preventing route plans being drawn on out-of-date or unverified data.

Crew workflow

· Daily — OOW reviews navigational warnings (NAVTEX, SafetyNET) and updates passage plan as needed.

· Weekly — ETO or Chief Mate downloads or installs ENC update batch; verifies all cells along the planned route are at the current ETRS week.

· Pre-departure — passage plan reviewed against current ENCs and AIO/T&P overlay; chart adequacy confirmed; ECDIS test routine logged.

· Annual — ECDIS performance test, alarm test, route-checking test per IMO Resolution MSC.232(82) Annex 4.

· 5-yearly — ECDIS hardware and ENC subscriptions reviewed at vessel renewal class survey.

PSC and vetting findings

· ENCs not up to date — most-common ECDIS deficiency under Paris MoU CICs.

· Type-specific ECDIS training missing for the model fitted (MSC.1/Circ.1503/Rev.1).

· Backup arrangements not in place (independent ECDIS, paper charts, or appropriate folio).

· Dummy 'route' file from training mode not deleted.

· T&P / AIO overlay not loaded; navigational warnings not transferred to the passage plan.