Source: https://guthlabs.ai/docs/instruments/tide-table-lookup-local-station/implementation/

instrument implementation / implementation-contract

# Tide Table Lookup (local station) implementation

A source-bound implementation contract for Tide Table Lookup (local station); deployment and executable qualification remain separate.

Status: **DISPOSED_UNVERIFIABLE_OFFLINE**Lifecycle: **implementation-contract**

## 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

[01**Overview**](<https://guthlabs.ai/docs/instruments/tide-table-lookup-local-station/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/tide-table-lookup-local-station/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/tide-table-lookup-local-station/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`