Free 2 month tastecard. I have an annual one which I use at least once a week. Gives 50% off food or 2 for 1 across your meals. Lots of restaurants on board, obviously many in London but I live in Kent and there are lots there too. I tend to book beforehand and tell them I'm using my card to avoid any problems and it's always been fine. I booked a half price dinner for 8 of us at the Hilton hotel restaurant last month.
Anyway, if you like eating out, it may be worth a try