Combine lemon juice and sugar in a small bowl or 2-cup measuring cup and mix well.
Add orange juice and light rum. Stir well.
Fill a 16-ounce glass half full of ice.
Pour the mixture into the glass.
Using a spoon, float the last three ingredients in order. This means you will slowly pour each liquid over the back of a spoon so that it doesn’t mix into the drink too much.