I think it doesnt even have to be a separate Bluewater fleet. The reason why Gaijin separated them in the first place was because of organizational constraints, on the current 5 line limit of tech tree organizations. Surely 1 line can be reserved for the Chilean Bluewater ships - since even in the suggestion its just 1 line.
Just need to like demarcate it or something, maybe add like a dotted line on the edge?