The MAS 561 was a motor torpedo boat (Motoscafo Armato Silurante) of the MAS 500 class whose purpose was to attack enemy ships, and anti-submarine and escort operations. Built in 1941 with the others of the 3rd Series, the MAS 561 in particular was captured during the 1943 armistice of Italy by the Italians of the RSI (Italian Socialist Republic) i.e. the allies of Germany before the end of the war, and modified to add two Breda-SAFAT (12.7 mm) single mount machine guns, to increase its effectiveness against enemy Allied boats and to be used as anti-aircraft against enemy aircraft. Eventually, it was taken by the Germans and sank with its entire crew on 23 April 1945.

Introduced in Update "Raining Fire", the MAS 561 replaced the old reserve boat (MAS 555). It is the first Italian coastal ship you will play, and thanks to its speed you will be able to approach enemy ships quickly and launch torpedoes or depth charges causing serious damage to the enemy ship or its direct destruction. The armament consists of two 12.7 mm and one 20 mm guns, giving you good firepower against coastal boats. However, it is very fragile to enemy hits having little armour and a small crew.