Cruising

Ahhh…  the Sapphire Princess…    This cruise ship pulled up outside my window as I was working at the AMP building in Circular Quay earlier this week.   It was my last day in the office and it’s arrival seemed to mean something for me…  I’m not sure exactly what.   It was the first time in that office that I couldn’t but to stare out the window.  
After a few minutes of Googling I learnt that the Sapphire Princess and it’s twin, the Diamond Princess were build just a few years ago in Japan and now sail around the world for P&O cruises.    I’ve never contemplated having a cruise before…  but these amazing looking super structures could change my mind.    This ship carries 2600 passengers, is 11 stories out of the water, has 750 cabins with their own balconies, 4 swimming pools and a wedding chapel!  
It would kinda be interested going on a short cruise and doing nothing but lying around a pool for a few days in the middle of the ocean.   The places they go to are pretty interesting too….    they go everywhere from Fiji to Alaska.  I was hoping the ship would pull out while I was there so I could see the streamers and hum the Love Boat theme.
Does anyone know why they have jets that look like aeroplane engines on the roof?