FM Johnston 1948 Porpoise. 15 July Entrance to New Post Walter Baranof I. Alaska. A school of about eight met the Yakobi about 3/4 mi off the en- tiance. They dart back & forth in front off the bow in a tack ing fashion. Will swim about 6-10 feet below the surface. Movement of the horizontal tail flukes is about 4 to the second. Our boat was traveling at 10 Kts & the porpoise would exceed our speed by half again that much (15 Kts). They turn sharply, rolling slightly to the inside in the direction they wish to take. The front flippers are extended down tail an angle of about 20° from the body while swimming on the straight-a-way - but when a turn is executed, the front flippers are raised almost to a horizontal position. While swimming in this fast manner they will