MS Stena Mersey is a RoPax ferry operated by Stena Line between Birkenhead and Belfast. She was built in Italy by Cantiere Navale Visentini. She is 26,500GRT and can carry up to 980 passengers in her two lounges, and can sleep up to 480 in cabins. She has four vehicle decks and room for around 200 lorries. Her maximum speed is 27 knots, but usually sails at 23 knots maximum.