Abstract: There is disclosed a method of monitoring a subsea installation comprising: providing data storage means in a subsea control module and storing data resulting from the monitoring of equipment of the installation in the storage means.

Abstract: Disclosed is a method of storing data on a tape medium in at least one data recording session employing a tape drive apparatus operable to record the data in accordance with a format specifying an unused area of the tape medium. The method comprises formatting the tape medium according to the format, and recording a tape medium identifier in the specified unused area of the tape medium.

Abstract: Data stored on a tape in a plurality of data recording sessions employs tape drive apparatus programmed to record the data in accordance with a format specifying a log of tape-usage information. The log is in the form of a data structure including a plurality of log sections in which tape usage information is recorded relating respectively to corresponding ones of the plurality of data recording sessions. The log sections together constitute a cumulative record of tape usage covering the corresponding plurality of recording sessions, each log section in respect of a recording session comprising an identifier of the tape drive apparatus used for that recording session and a count of the recording session.

Abstract: Data storage apparatus is provided for storing data on a tape in accordance with a format specifying a plurality of logs of tape-usage information and a data area for storing the data. Control means are programmed to update one of the logs for each usage of the tape, the logs being selected in turn for updating.

Abstract: A data transfer apparatus is described for transferring data between at least one transducer head of the data transfer apparatus and a data medium removably received in the data transfer apparatus. The data transfer apparatus is operable to monitor at least one data transfer performance characteristic, and to use results of the monitoring to set an indicator for access by the data transfer apparatus, for use in connection with a subsequent head-cleaning process using a designated head-cleaning medium, the indicator corresponding to an appropriate quality of head-cleaning process.