01 - Halve the pineapple lengthwise and carefully scoop out the flesh, leaving sturdy shells intact.
02 - Combine the scooped pineapple flesh, sugar, lime juice, and coconut water in a blender. Process until the mixture is completely smooth.
03 - Refrigerate the blended mixture until thoroughly chilled, then churn in an ice cream maker according to manufacturer instructions until creamy. If an ice cream maker is unavailable, freeze in a shallow dish, stirring with a fork every 30 minutes to break up ice crystals, until smooth and scoopable.
04 - Spoon the sorbet into the reserved pineapple shells, smooth the tops, and place in the freezer until firm, about 3 to 4 hours.
05 - Garnish with toasted coconut flakes or fresh pineapple wedges before serving.