If you choose to tip extra ask the person if they get to keep the tip. Policies vary by line but some people don't get to keep tips, they have turn them in to their boss for the tip pool anyway. Not only do they not get the money your making them work extra by making them turn it in.
11 cruises in 2012, 90 nights at sea visiting 15 countries
8 cruises in 2013, 56 nights at sea visiting 7 countries
Next cruise: None scheduled
PM me if you need a cruisemate for any Europe, transatlantic, or Panama Canal cruises
Date, ship, cost pp