Seashells she sells

 

Yes, we're still at the beach and this is what you make from what's left of the bar on the second to last night.

2 parts vodka
1/2 part grapefruit juice
2 drops grapefruit bitters
2 parts tonic water (or to taste)
1/2 part Tres Agaves margarita mix (to sweeten it a tad - grapefruit juice, tonic water and bitters funnily enough made it really bitter)

Stir in whatever container you have to hand and pour over ice in a chilled glass. Sip it while waiting on your friend to come back with a box of freshly steamed crab.

Yes, it's going to be hard to leave.