'Monastic' was a British naval minelaying operation in the English Channel to hamper any German naval interference in 'Neptune' (iii) (5 June 1944).

In order to increase the minelaying resources available to meet the 'Maple' (ii) requirement, boats of the 14^th and 64^th Motor Torpedo Boat Flotillas were transferred to the Portsmouth Command in May 1944, and as part of their efforts in support of 'Overlord', a number of special diversionary undertakings, including minelaying by these motor torpedo boats, was carried out on D-1.