Previous names

  • 1920 - 1941 White Heather
  • 1941 - 1946 HMS Manatee
  • 1946 - 1950 White Heather
  • 1950 Riis 1
Certificate no 2034
Status Registered


Function Leisure Craft
Subfunction Yacht
Location West Mersea
Vessel type Motor Yacht
Current use Private use
Available to hire No
Available for excursions No
Info required Yes
Web address


Builder McGruer & Co Limited, Dumbartonshire
Built in 1920
Hull material Wood
Rig Bermudan
Number of decks 1
Number of masts 1
Propulsion Motor
Number of engines 1
Primary engine type Inboard diesel
Boiler type None
Boilermaker None


Breadth: Beam
10.07 feet (3.07 m)
4.98 feet (1.52 m)
Length: Overall
57.15 feet (17.43 m)
Tonnage: Gross
Air Draft
To be confirmed



Built in 1920 by McGruer & Co.Limited, Clynder, Dumbartonshire, RIIS I is a twin screw motor yacht of pitch pine over oak, with a carvel construction. She has twin Ford Thornycroft engines of 44.76 kw each, installed in 1973. She was originally registered in Glasgow, later moved to North Wales and thence to the South East of England where she has remained. As HMS MANATEE she saw significant service during World War II when she was used as a patrol boat and for special operations. She took part in Operation Dynamo and later in the St Valery landings. She was returned to her owner in 1946 and sold on to a private buyer. She is now based at West Mersea, Essex.

We are lacking information on this particular vessel. If you have any information on this vessel past or present, please contact us.


ADLS News: Ostend to Anchor, pp16-17, Spring 2015 

Key dates

  • 2012

    Vessel selected for Avenue of Sail, Queen's Diamond Jubilee Pageant on 3 June 2012

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