The Buffer reports to the Executive Officer (second in command), and has a wide-ranging "roving commission" to supervise seamanship evolutions (activities) and issue directions to seamen as required, and advise "part of ship" Officers and Petty Officers on their activities. As such, directions and orders come with the 'line' authority of the Executive Officer.
The Buffer will manage major ship activities, such as: taking on equipment in harbour; a ship berths alongside in harbour; rigging for refuelling or stores transfer at sea; sending away a sea-boat; laying or recovering a buoy; the ship coming to a mooring.
The Buffer will often be involved in "Heads of Department" planning meetings, along with senior specialist sailors from other departments.
The Commanding Officer will usually call for advice from the Buffer with the Executive Officer in attendance, so that there is wide agreement and understanding between these three senior seamanship staff.