Tide Table Lookup (local station) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

source-required

Evidence ID

live-source boundary

Effect

Computation or source lookup only

Input and validation requirements

The instrument cannot produce authoritative numeric tide predictions offline or without station-specific harmonic constants and live data. Boundary, extreme-date, calendar-transition, and time-zone cases also require explicit rejection or documented conventions; silently extrapolating, fabricating values, or choosing a time convention could create unsafe boating information.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The interface must expose source, freshness, and held state instead of calculating from a nonexistent offline oracle.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json