a tip - what I do is pre-marinade the pineapple in dark rum and then after a while stooping it, I purée and chill it, after that make the mix in the normal way,
blend half of the pineapple, 8 oz. coconut milk and cream (if you have the cream), 8 oz. Bacardi, lime juice (at least half a lime - I usually go for 1 lime), and plenty of ice in a blender until smooth.
If you have the time and not the numbers, put the blending vessel in the fridge for another 20 minutes or so and then a final blast, pour and then add your garnishes - usually a Del Monte cherry and a wedge of lime. Should give you 4 hi-balls.