porpoise

1. (intransitive) Said of an air-breathing aquatic animal such as a porpoise or penguin: To repeatedly jump out of the water to take a breath and dive back in a continuous motion.Examples: "Urging them to join me, I raced in circles through the surging water, chased my tail for the children, blew spouts of foam through the sunfilled spray, porpoised to and fro across the river in shallow leaps that stitched the air and water into a table-lace of foam."intransitive

2. (intransitive) Said of an aircraft: to make a series of plunges when taking off or landing; or of a watercraft: to successively plunge up and down in the water.Synonyms: balloonintransitive