NR1, the US Navy's smallest and only research submarine, is due to arrive in Portsmouth on Thursday 8th May.

Boat owners who sight an orange submarine in the Solent tomorrow (Thursday 8th May) really can believe their eyes. The brilliantly marked NR1, the US Navy’s smallest and only research submarine, is due to arrive for a visit to Portsmouth Naval Base.

NR1 is 44 metres long and carries a crew of two officers, eight enlisted men, and two scientists, and can dive to depths greater than 700 metres. She is the first deep submergence vessel to use nuclear power but, as her top speed is just five knots, her support ship Carolyn Chouest will tow her into harbour.

During a recent underwater survey of Norwegian fjords and harbours, NR-1 discovered 26 shipwrecks during a 12-hour period.