Seantral is in production at seantral.com: sea conditions for 300 Italian locations, hour by hour, with a score for eight activities, free and with no account. Indicative forecasts, never a safety assessment.
It is the example of the method in production: from brief to prototype, then a domain of its own, with tests that only ever tighten, probes on the published site and public post-mortems of what broke. From proto to production.