Step 1.
- In a shaker, combine the light rum, fresh lime juice, orange juice, simple syrup, and grenadine.
Step 2.
- Fill the shaker with ice and shake vigorously for about 15 seconds.
Step 3.
- Strain the mixture into a highball glass filled with crushed ice.
Step 4.
- Top with soda water and stir gently to combine.
Step 5.
- Garnish with a sprig of mint.