Shake all ingredients with ice for 15 seconds, strain into coupe. Either no garnish, or garnish with lime twist or lime wheel.
Originally made with Bacardi 1909 Superior Heritage, a 89 proof white rum, that I believe is out of production. I've been making this lately with the recently introduced Diplomatico Planas (94 proof), but any standard 80 proof light rum should work fine.
Part of my 2015 "Daiquiri-palooza" of weekly daiquiri riffs for an entire year. Name after the city where Becherovka is produced, Karlovy Vary (aka Carlsbad).