Build, fill glass with crushed ice
1/2 oz fresh lime juice (1.5 cl, 1/8 gills)
1 oz dry vermouth (3 cl, 1/4 gills)
1 oz light rum (3 cl, 1/4 gills)
1/2 tsp sugar (2 dashes)
Fill with soda
Swizzle until glass frosts
Serve in a highball glass (9.0 oz)
