in the context of "바라던 바다!", 바다 is a compound of 바 (reference to a thing mentioned previously) and -다 (declarative suffix). So that sentence just means "That's what I wanted!"
in the context of "바라던 바다!", 바다 is a compound of 바 (reference to a thing mentioned previously) and -다 (declarative suffix). So that sentence just means "That's what I wanted!"