Courtesy National Zoo

Sad news from the Smithsonan’s National Zoo today, with the announcement that Gunnar, a 38-year-old gray seal, died last week. Gunnar, who arrived at the zoo in 1979, lived much longer than the normal lifespan for his species, in which the average life expectancy for males is 25 to 30 years.

Before moving to the zoo, Gunnar was in the employ of the United States Navy, which trained him to conduct underwater maintenance missions during the Cold War. Yes, he was a Navy seal.

Diving up to 475 feet deep for periods as long as 20 minutes, Gunnar was capable of inserting and removing equipment, using a screwdriver and turning large wheel valves.

Gunnar was born in Iceland in 1973 and joined the Navy when he was six months old. At the time, his species was not found in any U.S. zoos, which made him a prized breeder. He fathered two pups in 1983 and 1980. Both moved to Adventure Aquarium in New Jersey, but are scheduled to finally return to the National Zoo in September.