Buffer is the colloquial title for the senior seaman sailor in a Commonwealth of Nations Navy ship. The formal title is chief boatswain's mate. This person is typically a chief petty officer or petty officer in frigates or destroyers, and in larger ships may be a warrant officer. In smaller ships, such as a patrol boat, the buffer may be a petty officer or leading rate. The commanding officer may occasionally call for advice from the buffer with the deck officer and executive officer in attendance, so that there is wide agreement and understanding between the senior seamanship staff.