Thomas B. Crowley Sr., 79, head of the giant maritime company launched by his father 102 years ago with one rowboat. Crowley, chairman and chief executive officer of Crowley Maritime Corp., presided over a shipping empire that included more than 400 vessels and 5,000 employees. The vessels range from tugs and barges to a fleet of 28 cargo ships. Still owned by family members and workers, the company has annual revenues of $1.2 billion. Its numerous business lines are conducted through two major operating units: Crowley American Transport Inc., based in Jacksonville, Fla., and Crowley Marine Services Inc. of Seattle. Under Crowley's direction, the company pioneered bulk petroleum barge service on the Pacific Coast. In 1958 it performed the first commercial resupply of the Distant Early Warning Line installations in the Arctic. In San Francisco on Thursday of prostate cancer.