- Class: Royal Yacht
- Displacement: 4,715 tons
- Dimensions: 412 (oa) 380 (wl) x 55 x 15.5 ft.
- Machinery: Two geared steam turbines, one shaft 12,000 shp = 22.5 knots
- Complement: 300
- Designer: Sir Victor Shepheard
- Builder: John Brown & Co. Ltd., Clydebank, Scotland, 1954
- Service: Laid down Jun 1952, launched 16 Apr 1953, and commissioned 11 Jan 1954. Britannia served The Queen and the Royal Family for 44 years, during which she made 968 official voyages. She was decommissioned on 11 Dec 1997 and is now moored as a museum ship at Edinburgh's historic port of Leith.