Sprinkle gelatin over water. Let sit 10 minutes to bloom.
In saucepan, heat, but do not boil, coconut milk, sugar, honey and vanilla, stirring to dissolve sugar. Add gelatin mix to coconut milk mix. Stir to dissolve completely. Pour evenly into custard cups. Refrigerate at least two hours.
Rum Sauce
Place all ingredients in sauce pan. Simmer on low heat until mango softens. Puree with stick blender. If sauce is too thick, add more water. Taste and adjust sugar if necessary. Strain and cool.
Place a 1½ ounces of sauce on plate. Unmold Panna Cotta. Loosen lightly with butter knife and invert. Top with toasted coconut.