A.a 2-second blast every 20 seconds B.a 4-second blast every 20 seconds C.an 8-second blast every 30 seconds D.a 10-second blast every 30 seconds
A.turn off all lights that interfere with the navigation lights B.turn on all available working lights on deck C.ring the bell rapidly for five seconds once a minute D.display two black diamonds in a vertical line during the day
A.Aye Aye Sir B.Right 15 degrees rudder C.Rudder is right 15 degrees D.No reply is necessary,just carry out the order