Possible Clues:

• Nautical steering device
• Director of 'Argo'?
• ___ Girls, chorus line dancers
• Saw off stairwell leading to bar on the boat
• £50 in bank that navigator gets hold of
• Row about two pounds wanted for a steering device
• One directs roofer to add extra line
• Bar on a boat - the one the navigator, of course, is holding on to
• It helps to guide one cultivating crops
• The bar on a boat is called what? 'The Navigator' of course!