An underwater combat form of the Core Gundam docked with the Hermes Armor. As the satellite System allows the Core Gundam to improve the capability of the Planet Armor, the Hermes-Mercuone Gundam was intentionally built as a mobile suit limited to underwater battles. It is one of the few dedicated to underwater operations, with most mobile suits capable of operating underwater being amphibious units or also having ground combat capabilities.

The Hermes-Mercuone Gundam has a silhouette with large fins across its entire body and was designed to have excellent mobility in the depths of the sea, and the armor sections with improved pressure resistance have also enhanced its defensive capabilities. It has a large backpack with large fins for attitude control and water jets for underwater propulsion. It is also equipped with active sonar for detecting enemies underwater and its armaments include the Water Needle Gun equipped with Underwater Bits and Fin Zambers.also the harpoon gun can improve the gundam combat capability without any Hand weapon

Harpoon Gun
A portable firearm dedicated to the Mercuone Gundam. Mounted on the right arm,improve middle and long range combat capability.

Boots of Hermes
Just like The Winged Shoes,boots of Hermes improve the underwater Propulsion ability,allow Hermes-Mercuone Gundam to do some more flexible maneuvers

（中国语注意）
赫尔墨斯装甲
由于水星没有卫星，所以只能让墨丘利的希腊同胞赫尔墨斯来担当重任了，这款装甲主要是加入赫尔墨斯的元素，和提高水下推进能力。

鱼叉枪
为了提高水星1装甲失去武器后的中远距离格斗能力，在右臂上增加了鱼叉枪提升水下攻击距离。

赫尔墨斯之靴
这东西仿照赫尔墨斯的飞天靴设计，所以加了两个看上去像鱼鳍的小翅膀，本质也是为了提升机动性（两条腿不对称真的能提高机动性嘛）更多的其实还是外观上的设计大于实用性。

肩部喷水口
这个部分倒是真的为了提升机动性做的，类似水中型高达的两组肩部喷水口。

杂谈
卫星系统刚好画了一半了，庆祝一下。不过由于泰坦（土卫六）和特里同（海卫三）两组装甲还挺难想的，所以可能会拖得时间很长了。这款也是延续了卫星装甲只改动五个部件的传统，头部就不做大改啦。