Captain Jack is the captain of the boat in the episode Booze Cruise. He was in the Navy during the Gulf War and had several close calls with death. The day he returned from war, he proposed to his future wife. However, they divorced and he married at least one more time.
He had many problems with Michael Scott, who challenged his authority a few times. He had a brief one-night-stand with Meredith but it was interrupted when he heard Michael trying to convince the passengers that the boat was sinking and that Jack had abandoned them. By the end of the episode, he got Roy and Pam's engagement almost through to marriage.