A study of the behavioral response of Indo-Pacific humpback dolphin to vessel traffic was presented. Results indicated that dolphins performed longer dives when they were situated in an area of heavy vessel traffic or they were approached by a travelling vessel. Results also indicated that resident dolphins might have already established a sophisticated association with travelling vessels. They might flee, give undetermined responses, pass by or even approach the boat, depending upon the type of vessel and the relative distance. Whilst slow-moving vessels appear not to cause immediate stress on the dolphin community, high-speed vessels are the main concern from the perspective of conservation because they often cause disruption of behavior and social life.