A method of obtaining data from a subsea control module of an underwater well facility is provided. The method comprises: providing a tag which stores data relating to the module, the tag being operable to wirelessly transmit the data to a reader device; locating the tag at the module; providing a reader device; and interrogating the tag using the reader device, such that the tag is caused to wirelessly transmit the data to the reader device, wherein the tag is communicatively connected to a subsea electronics module for receiving information therefrom.