The MAS 429 was one of three Italian MAS 427-class artillery patrol boats. Built in 1919 at the Societa Veneziana Automobili Navali shipyard in Venice, the boats had wooden hulls and no armor protection. The main armament was a 76 mm Ansaldo naval gun of the 1916 model. While such armament was formidable for a small naval craft, firing the gun at full speed was nearly impossible due to its strong recoil and the boat's heavy rolling. The MAS 429 differed from the other boats in its class because it had a shorter hull, resulting in lower displacement.

Although the boats were practically completed in 1919, they did not enter service until much later: the MAS 427 and MAS 428 were not commissioned until 1925, and the MAS 429 was not commissioned until 1927. The boats carried out patrol duties off the coast of Italy and did not participate in any significant events. By the late 1930s, all three boats had been removed from service. The MAS 428 was scrapped in 1937, the MAS 429 in 1938; the MAS 427 sank earlier, in 1929.

The MAS 429 was introduced in Update 2.57 "Heavy Cavalry". It is a fairly large boat with mediocre mobility, but it has a powerful gun capable of destroying enemy boats with a couple of well-placed hits. Its slow reload time and lack of armor protection prevent it from staying under enemy fire for long, making it better suited to the role of a sniper.