The man was approximately 40 yards from shore when he suffered an apparent bite to his calf, officials say. He was able to make it to shore under his own power and was administered first aid. The man suffered lacerations to his calf and is in good condition, officials say.
The shark was estimated to be 8 feet in length, the department said in a press release. Authorities remain at the scene and are advising beachgoers to stay out of the water.
The incident is the second shark attack of the year in Hawaii. The first one took place on January 2.