He had been on 9 patrols mostly aboard The Jack. The Jack sank the 9th most in tonnage out of 200 US subs. Calvert was the TDC operator...he with the most responsibility for getting the fish to their targets. The stories of these patrols are fasinating.
Calvert left the Navy at age 52 as Rear Admiral. He was the third nuke skipper, taking the Skate to, and surfacing at, the North Pole for a first. This voyage is described in a prior book by Calvert which I haven't tracked down ...yet.