Thanks for raising awareness of the breast cancer societies - walk strong.
Christmas is certainly celebrated here and there will be midnight mass at the RC church Christmas eve. Many of the other denominations will be celebrating the birth of Christ too.
The town is brightly decorated and most restaurants and bars will operate during the holidays. Gift shops and other retail businesses may be closed Christmas day and Boxing day (the day after Christmas. However your hotel will be able to set you up with snorkel and dive trips etc.
It is a great time of good will. There will be turkey dinner specials everywhere.
You will have a great visit.