Complex sentence: In early 1953 a commodore (a captain that had the title commadore) went aboard the USS Nantahala AO 60 to evaluate the captain of the ship for promotion to rank of Captain.
Split into simpler sentences: In early 1953 a commodore (a captain that had the title commadore) went aboard the Uss. Nantala AO 60 to evaluate the captain of the ship for promotion to rank of Captain.