The Minoru II was a motorboat built in 1921 by George Feltham of Old Portsmouth. Measuring 40 feet in length with a 12-foot beam, she was powered by a Calvin Atlantic 32HP engine. The vessel could accommodate 60 passengers and crew, and had a service speed of approximately 10 knots.

Owned by John William Cottrell, a member of a longstanding family of Watermen and Wherrymen operating in and around Portsmouth Harbour, the Minoru II was named after King Edward VII’s racehorse. Between the First and Second World Wars, she operated from The Camber docks in Old Portsmouth, providing pleasure trips around Portsmouth Harbour for the public. Additionally, she was used to deliver the Daily Mail to yachts in the Solent during Cowes Week and to transport Campion's bread to naval ships in the harbour and at Spithead.

During the Second World War, the Minoru II was requisitioned by the Royal Navy and participated in the Dunkirk evacuation, where she sustained significant damage. Following her return, she served as a fire float in Portsmouth Harbour for the remainder of the war.

Photographs from April 1941 show the Minoru II in The Camber, visibly damaged from her Dunkirk service. These images were preserved by a firefighter who recovered them in the late 1990s, and they confirm the vessel’s wartime condition and presence in Portsmouth Harbour.

After the war, John William Cottrell sold his boats and business. The Minoru II remained operational in Portsmouth Harbour as late as 1984, when she was observed moored alongside the Gosport ferry. It is believed she was active on the River Hamble during the late 1980s. More recently, the vessel has been reported to still exist under the name Camberlee, having been fitted with a cabin.

• Photo 1: The Minoru II slips into Portsmouth Harbour carrying sightseeing passengers, with John William Cottrell (white cap) at the helm, circa 1932.
• Photo 2: Minoru II picking up passengers in The Camber for a pleasure trip, 1923.
• Photo 3: Silver Spray and Minoru II during trips around the forts, Southsea seafront, 1920s.
• Photo 4: Fireboat Paul AFS with Minoru II (lighter coloured boat) on the right, Portsmouth Camber, April 1941, showing damage from Dunkirk.
• Photo 5: Minoru II on the left with John William Cottrell onboard, April 1941.
• Photo 6: John William Cottrell (flat cap) on an unknown boat, The Camber, April 1941.