The tide tables are printed, and the mistake is on page nine
The tables are set by hand from the Admiralty predictions, as they have been for sixty years, and a transposition crept into one week in August. The harbour office has printed a slip for the inside cover.
Everything else has been checked twice.
A demonstration: Saltmarsh and its Ledger are invented. Built by plinth from EDN and Markdown; the front's further pages are real pages and are also pulled in place where scripts run, and a click from the front to a story and back swaps the page in place, every address still a real page.