Weather stations aboard buoys in the Atlantic Ocean, west of Ireland, provide the UK Met. Office with weather data via satellite telemetry. The data help provide a more complete picture of weather conditions at sea and function as an early warning system. Each CR10X Measurement and Control System records air temperature, wind speed and direction, relative humidity, wave height (which can be up to 10 metres during storms), and wave period—the time between peaks and troughs (averaged over 17.5 minutes). The dataloggers are retrieved once every two years and have always been found in perfect condition. Weather instrumentation will soon be installed on lightships in the English Channel and provide additional data.