Possible Clues:

• Might he deal with a steer on a farm?
• It turns the rudder
• One that guides the plough may guide the vessel
• Ploughman makes lines in a row
• Bar that turns rudder in small boat
• Dirt farmer
• Horizontal bar to turn rudder
• Rod used to turn rudder on small boat
• Even more sick of farming on board after tea
• Perhaps it's the farmer that may have a steer