Forecast information from National Oceanic and Atmospheric Administration (NOAA) for coastal waterways in South Texas. Bays and waterways forecast south of Port Aransas: Forecast for Corpus Christi Bay and Laguna Madre waters from Port Aransas south to Baffin Bay Coastal Waters Forecast – Port Aransas to Matagorda Ship Channel: Forecast for the Gulf of Mexico from Port Aransas to Matagorda Ship Channel, up to 20 nautical miles from the coast Coastal Waters Forecast – Port Aransas to Baffin Bay: Forecast for the Gulf of Mexico from Port Aransas to Baffin Bay, up to 20 nautical miles from the coast