All Tidal Data is ©Crown Copyright. Reproduced by permission of the Controller of Her Majesty's Stationery Office and the UK Hydrographic Office (www.ukho.gov.uk). No tidal data may be reproduced without the expressed permission of the UKHO licencing department.
PDFs and tables ©2014-2023 James Bithell
PDF format tidal predictions for Porthmadog for the next 12 months are available via James Bithell's site, embedded below