Admiral Cowan is the lead vessel of the Estonian Navy Mineships Division and also the first of the three modernised Sandown class minehunters received.

[2][3] After commissioning, Sandown carried out an extensive programme of trials,[3] and was not fully operational until December 1992, having suffered problems with her sonar outfit.

[5] On 16 January 2000 Sandown located the wreck of the sunken scallop dredger, the Solway Harvester.

[6] Sandown spent July 2002 on a Joint Maritime Course, after which she deployed to the Mediterranean to take part in the Argonaut 02 exercises, which lasted until Christmas.

Sandown was also deployed as part of Operation Telic, to clear mines in the Persian Gulf, and sweep passages into Iraqi ports.