Watermelon Slushy Martini

Stir the sugar and water together on low heat until dissolved. Cut the watermelon and blend until smooth. Mash through a sieve and throw away the pulp. Stir the sugar solution into the watermelon juice. Pour into a shallow baking pan and freeze. After 4 hours, mash with a fork and stir well. Freeze overnight. When ready to serve, transfer to blender, add Buckeye vodka and lime juice and pulse until smooth. Present in a margarita glass.