
Navy rum is a dark, full-bodied rum style, often bottled strong, rooted in the British Royal Navy’s rum ration, traditionally blended from British Caribbean territories like Guyana, Barbados and Trinidad.
Navy rums differ in strength: Pusser's Blue Label is 40% (42% in the US), its Gunpowder Proof 54.5%, Smith & Cross 57%. Another one works one for one. A 40% bottle in place of a 57% one makes a weaker drink, and the reverse a stronger one. Without navy rum, use a dark Demerara rum from Guyana, the backbone of the old Royal Navy blends. Avoid sweetened “navy” rums such as A.H. Riise, at about 97 g of sugar per liter.
Overproof rum
Rum bottled at 57% or more, in any style. A 63% white one such as Wray & Nephew brings the heat but none of the molasses depth. In place of a 57% navy rum, use about a tenth less; with stronger rums, less still.
Dark/blended aged rum
Dark is a color, not a style: most are 40%, and some are lightly sweetened. In place of a 57% navy rum, use about 1.4 times the measure or accept a weaker drink.