Miami To Bahamas Cruise

I'm traveling to the Bahamas, I fly straight or go on the cruise in Miami and the Bahamas?

Never beeen in the Bahamas. Is there much to make it do not cost much if I fly straight there and stay there for four days? Or a cruise to be better? I cruise in Miami Florida Key West, then two Islands Of The Bahamas in two days. I would like to see more of the cruise, but it is limited to the vessel at night and I would just to Nassau Bahamas for one day) per day in the Bahamas to be sufficient for the experience? Cruise or fly straight there? What are your thoughts experiences? Thank you