HGUC 008 Gogg 1/144

The MSM-03 Gogg is an amphibious mobile suit introduced in Mobile Suit Gundam. 

The Principality of Zeon had developed the ground use MS-09 Dom, but its nuclear reactor's output was insufficient for powering mega particle cannons/guns. Increasing the reactor output would require better cooling capacity, and the most efficient method was water cooling. Therefore, in November U.C. 0078, the MIP and Zimmad received orders to develop amphibious MS which can use seawater for cooling. In addition to the use of mega particle weapons, the amphibious MS can reach its destination by traveling through the sea on its own, allowing it to fight in areas away from Zeon's frontline bases.