I am writing this review as a first time cruiser on P&O, and therefore the Britannia.
We flew to Barbados, from Gatwick on a Dreamliner, which had a little extra legroom, always appreciated!
On arrival in Barbados, we were lined up on the Tarmac and immediately put onto a mini bus which took us to the port, we were then processed in the hangar rapidly, photos taken, passports checked, credit card details, we were then free to board the ship (10 minutes after walking into the hangar.) We boarded the ship and were taken to deck 9 in a lift, and went to our cabin, no problem in finding them, evens on port side, odds on starboard!
The cabin had a reasonable size balcony, the bathroom was adequate, but I personally liked the glass screen on the shower, far less water left on the floor, and no shower curtain sticking to you! A good sized TV and a 2 seater sofa in the room, plenty of clothes storage in the open wardrobe with a tall boy beside for the smaller folded item, the hairdryer was plugged in by the kettle and all plugs were Uk 3 pin. A good amount of tea, coffee, milk, sugar and biscuits all of which were replaced twice daily.