ENC Chart Distribution Service (PAYS)

What sets an ENC distribution service apart

An ECDIS only works legally and safely if it shows up-to-date official charts. Those charts come as electronic navigational charts, ENCs, issued by national hydrographic offices and collected by regional centres. A distribution service is the commercial layer between the authorities and the ship: it supplies the ENC cells, issues the permits that unlock them, delivers the weekly updates and keeps track of what each vessel holds. Pay-as-you-sail, often shortened to PAYS, is a licensing model in which the ship pays for the cells it actually uses over a period, instead of buying a large fixed set of charts for a whole year. That makes cost follow the route, but it also moves part of the responsibility for chart coverage into the voyage planning.

Main elements

• ENC data in the international exchange format, produced by official hydrographic offices
• Regional coordinating centres that collect and quality-check ENC data and pass it to distributors
• Permits and data protection, so the chart data can only be opened with a licence for the ship and the ECDIS
• Update packages that apply corrections, usually weekly, and sometimes in between for urgent warnings
• A planning tool or portal where cells are selected, ordered and activated for a route
• Licence reporting and billing, which differs between fixed subscriptions and pay-as-you-sail

Selection and sizing

• Licence model: pay-as-you-sail suits changing routes, a fixed bundle suits repeated trade in a defined area
• Coverage of the planned routes at the right scale bands, from ocean to harbour
• Compatibility with the installed ECDIS type and its permit system
• Delivery of updates by email, satellite or a portal, and the data volume that the ship's connection can handle
• Billing rules: when a cell counts as used, how long a permit lasts and what happens when a voyage changes
• Support hours for urgent permit or data problems, particularly for ships operating far from shore

Regulations and class

SOLAS Chapter V requires ships to carry up-to-date nautical charts and publications for the intended voyage, and an ECDIS with official ENC data may satisfy the chart-carriage requirement. Port state control inspectors check whether charts are current and whether the ECDIS has full coverage of the route. The data format and protection scheme are set by the International Hydrographic Organization. The service provider's role is regulated indirectly, through the requirement that the data are official and complete, and many providers have their delivery service certified, for example through a type-approval scheme of a classification society.

Typical faults

• Missing or expired permits, so a cell that is installed in the ECDIS still cannot be displayed
• Gaps in coverage at the planned route, discovered during voyage planning or at an inspection instead of at the time of ordering
• Failed or incomplete weekly updates, leaving charts out of date by several weeks
• Version mismatch between the ECDIS software and the format of the supplied data
• Unexpected billing, for example when a cell is activated on the planning computer but never used at sea
• Bandwidth problems, where large update packages do not arrive over a limited satellite connection

What to look for in a supplier

• Use of official ENC data from the hydrographic offices, with a clear statement of coverage
• Compatibility confirmed for the ECDIS models on board, including the permit handling
• Transparent licence and billing rules, with a clear definition of when a charge starts and stops
• Flexible update delivery, suitable for slow or expensive connections
• Round-the-clock support and a documented procedure for permit and data problems

Before departure, check the chart coverage and the permit status of every cell along the planned route and its alternatives. The easiest time to find a missing cell is in port, with a working connection.