Hi I am visiting Sanya on a cruise in June 2013 I am a British citizen do I need to organise a visa

If you want to visit the city, you need to get a visa, but you can get on upon your arrival there or you can get one in UK in advance.

It is not necessary to take different currency directly along your journey, but it is suggested to change some when you reach any areas of China. For instance, you can go to the local Bank of China to exchange some CNY.