The boat that oversees other boats, land, and people is usually a warship. They're the big boats that oversee everything around them. And if anyone steps out of line, a warship can take care of it.
This huge warship is run by Genghis Khan (かん), the famous warlord. Really, what did you expect? Who else is strong enough to captain a warship but him?
Currently there are no similar looking kanji which exist in the WaniKani learning system