the route which were more susceptible to harsh storms when moored at the exposed Portpatrick harbour on the Rhins coast. The calmer safer waters of the loch allowed larger ships to ply the route as demand increased. Second World War During World War II the loch was busy with wartime activity. Cairnryan became "No. 2 Military Port", an important secondary large-scale port facility that was available for use should facilities on the Mersey and the Clyde became unavailable due to enemy bombing. Construction of port facilities began in 1941 and two large piers the North Deep and the South Deep, serviced by a dedicated railway line, were completed by 1943. A total of of quayside was available, although the facilities were never used to their full capacity as the Clyde and Mersey never received the crippling bomb damage that was feared. The harbour was used as an import point for troops coming from the US after 1942. Only one of the two piers still stands today, and it is unusable due to the poor condition of the wooden piles (the pier has been unused since a small section collapsed with tragic consequences in the 1990s). With the U-boat menace in the Atlantic taking a heavy toll on merchant shipping the area became an important centre for anti-U-boat operations. Flying boats operated from the loch to protect allied shipping making its way to Liverpool or Glasgow either via the North Channel or the Firth of Clyde. There were two RAF stations on the loch, RAF Wig Bay operating from Wig Bay near Kirkcolm and RAF Stranraer operating from the town. Just north of Cairnryan are what looks like a number of concrete 'boats' resting on the shore - these too are a legacy of the second world war. They are 'Beetles' from the Mulberry harbour project. The beetle pontoons were used to hold up the 'Whale' roadway sections, with four of the whales being built at Cairnryan. With easy access to the North Atlantic, Loch Ryan was used as the surrender destination for the U-boats which were out in the Atlantic in 1945 when hostilities ceased. The U-boats and their crews were held at Cairnryan, before the boats were finally towed out into the Atlantic and sunk. Other wartime activity on the loch included construction of target rafts made out of wood and cork, which were built in Stranraer then floated