I am not sure you'd like a Chinese name that has that meaning. The word for "God" or "king" in Chinese is 神, 主, 皇, 帝, 朕 but people don't use these words in their names.
If you want something that carries a similar meaning you might want to look into using words that symbolizes "god" or "royalty" instead, like the word "dragon" 龍.
The word for "sea" is 海. These following words also means "body of water" 洋 (ocean), 江 (river), 河 (river), 湖 (lake)