I got 2/3rd of the way making a Ramos tonight after my final shaking (I dry shake last, after a 40~g ice-fully-melted shake), only to realize I was out of soda water. There's no going back - so browsing my fridge for anything carbonated, I picked a can of Fever Tree Ginger Beer. And know what? Not bad! Makes sense it would taste alright - kind of a cross between a Gin Gin Mule, minus the mint? Maybe I'll use ginger syrup or muddle a touch of ginger next time? Salvaged all my shaking at least!