[1] From 1982 to 1986, Tranquill served as the head football coach at the United States Naval Academy, compiling a record of 20–34–1.
Tranquill was the 32nd head coach for the United States Naval Academy Midshipmen located in Annapolis, Maryland and he held that position for five seasons, from 1982 until 1986.
After the 1990 season in which Virginia attained a #1 ranking behind a potent offense, Tranquill became the quarterbacks coach for the Cleveland Browns from 1991 to 1993.
After a brief retirement, Tranquill joined the Rhein Fire of NFL Europa where he served as the quarterbacks coach for one season.
In January 2009, he was hired by Frank Spaziani to become the offensive coordinator and quarterbacks coach for Boston College.