Take the proportions of a daiquiri, smash them together with the premise of a Trinidad Sour, and you get ...
1 oz Smith & Cross rum (I think any other rum would be drowned out, but the drink would still be good)
1 oz Angostura bitters
1 oz lime juice
3/4 oz tea-infused simple syrup (make very strong tea; add equal amounts tea and sugar)
It's spicy and bracing from the bitters, but the rum comes through. Very summery, but not in the light crisp manner of gin and tonics.