| Raid on Porto Buso | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Part of World War I | |||||||||
 Italian destroyer Zeffiro at Venice | |||||||||
| |||||||||
| Belligerents | |||||||||
 Austria-Hungary |
 Italy | ||||||||
| Commanders and leaders | |||||||||
|
Johannes Mareth |
Arturo Ciano | ||||||||
| Strength | |||||||||
|
68 servicemen Several motorboats and whalers | 1 destroyer | ||||||||
| Casualties and losses | |||||||||
|
11 killed 48 prisoners 1 motorboat sunk 1 whaler sunk 2 motorboats seized | None | ||||||||
The raid on Porto Buso was an assault launched by the Italian Royal Navy on an Austro-Hungarian naval station and border post located in Porto Buso island, in the Marano-Grado Lagoon, in the first hours of 24 May 1915, the day when the Kingdom of Italy entered World War I on the side of the Entente. The incursion became the first offensive action of the Italian Navy in the conflict, and ended with the destruction of the naval outpost, the sinking of a flotilla of small vessels and the capture of the majority of the Austro-Hungarian garrison. The action eventually resulted in the withdrawal of all Austro-Hungarian forces from the nearby town of Grado and neighbouring islands during the subsequent days.