This one surprised me enough to write down. I don't usually care much for coconut water; nor apparently does my wife, who bought a small carton only to take a small sip and immediately declare her disgust. Using the remainder immediately became my challenge of the evening.
2 oz Bak's Bison Grass vodka (other brands would presumably be fine)
3/4 oz thyme syrup (fairly rich with a small touch of honey in my version)
1 1/2 oz coconut water
1 1/2 oz "cryo-juiced" cucumber juice*
1 oz lemon juice
Stir vigorously over ice and add a quick charge of soda water. Alternatively, combine the above in the appropriate proportions and charge the whole thing in your soda siphon.
*This stuff is amazing. I found the recipe (or method, really) in Kevin Liu's excellent new book (the companion blog reprints occasional sections for those of you who want a representative sample) and have been making it every week since then. It's delicious and couldn't be easier. Just slice a cucumber or two into very thin wheels (a mandolin is nice for this) then pop them into a resealable plastic bag and chuck into the freezer. Once frozen, pull the bag out, let the cucumbers thaw completely (I recommend a drip tray from personal experience) and then return to the freezer for a second go. Once fully frozen and thawed again, pop the bag's top and pour off the resulting juice, squeezing the cucumbers through the bag to extract every drop you can. One reasonably sized cucumber seems to yield about 4-5 oz of bright green juice. Don't toss the drained wheels, either - you can drop them back into a pitcher to make cucumber water.