There is a lot to do though most resorts will cater to your every need. There are several craft markets and duty free stores abound. Bring in a return plane ticket and you can purchase tax free items such as liquors, perfumes, and jewelry. There is plenty to eat in Mobay. Authentic Jamaican cooking and some American mainstays like hamburgers.
Breakfast here is terrific.
Margaritaville is a party waiting to happen fit with a slide into water though once it ran out of margaritas. Many hotels offer boat rides in the bay. Private companies also have party yachts on which to cruise away your worries. A nighttime cruise through the bay is very pretty as the mountains rise up over the city and tiny points of light mark Jamaican homes. Mobay is a good point of operations to use if you wish only to explore the nearby area.