P&O Ferries until its closure on 30 September 2005. The Bilbao route remained as the only Portsmouth operation, until on 15 January 2010, P&O Ferries announced they would withdraw the service at the end of Pride of Bilbao'''s charter. The vessel completed her final voyage on 28 September 2010 and was returned to Irish Continental Group, from whom she had been chartered since the route's inception. This marked the end of P&O's operations from Portsmouth. North Sea P&O's involvement in the North Sea ferry routes began with a 35% stake in North Sea Ferries owned by its subsidiary General Steam Navigation Company. North Sea Ferries had begun operations on 17 December 1965 sailing on the Hull–Rotterdam route, a route which critics predicted would not survive. The numbers proved them wrong, however, and in the first year, 54,000 passengers were carried. By 1974, demand for capacity was greater than could be supplied, and two vastly bigger vessels, and , which were at that time the largest ferries in the world, were introduced to the route. The two vessels and Norwave were transferred to a new route, Hull–Zeebrugge, operating a nightly service departing 30 minutes after the Rotterdam service sailed. The two routes remained unchanged, with the exception of the Ministry of Defence chartering Norland for service with the British Task Force to the Falkland Islands in 1982. The two routes were becoming increasingly popular, and in 1987 the larger and were introduced on the Hull–Rotterdam route, the two displaced vessels moving to Hull–Zeebrugge and the sale of both Norwind and Norwave. As part of the success of the routes, dedicated freight routes were introduced from Teesport to both Rotterdam and Zeebrugge on a nightly basis. However, the ships quickly began to struggle to cope with demand, and in 1994 new superfreighters were introduced on the Hull routes. A new river berth was therefore constructed to accommodate the freight only vessels, however they were still small enough to pass through the lock at King George Dock if required. By 1996 P&O owned a 50% stake in North Sea Ferries, the other 50% owned by Royal Nedlloyd Group. In a multimillion-pound deal, P&O purchased Royal Nedlloyd Group's stake, and North Sea Ferries was rebranded to P&O North Sea Ferries. Continuing success saw the purchase of two new superferries weighing 60,000 tonnes from Fincantieri, entering service in 2001 as and and once again holding