Complex sentence: Promoted to Lieutenant-Commander on 16 October 1982, he commanded the submarine from 1981 to 1983, receiving a promotion to Commander in June 1986 He commanded the submarine from 1986 to 1989.
Split into simpler sentences: Promoted to Lieutenant-Commander on 16 October 1982, he commanded the submarine from 1981 to 1983. Receiving a promotion to Commander in June 1986, he commanded the submarine from 1986 to 1989.