'Messer' was a German naval minelaying operation in the Ligurian Sea by S-boote and the ex-Italian torpedo boats TA 25 and TA 29 of Korvettenkapitän Wirich von Gartzen’s 10^th Torpedoboots-Flottille (20/21 June 1944).

During this operation, TA 25 was torpedoed and sunk by US PT-boats. Over this same period the Italian destroyer Grecale and motor torpedo boat Ms 74 delivered British and Italian 'charioteer' human torpedoes to the area of La Spezia, and on 22 June these penetrated into the harbour and sank the heavy cruiser Bolzano, which was under repair for eventual German service. On 26 June these same forces sank the heavy cruiser Gorizia, also under repair for German service, to block the entrance to La Spezia.