Combine all ingredients except for the rind in a small saucepot, simmer for 5 minutes. Add rind, let steep for 5 minutes. Pour into a bowl and cool over an ice bath.
Mint Vinaigrette: In a small sauce pan heat the vinegar and add the mint sprigs. Reduce by half. Add the remaining ingredients, except the oil and cool. Remove the mint sprigs.When cool whisk in the oil.
To Assemble: Toss the watermelon and rum together, set aside. Toss the crab in half of the vinaigrette. Toss the greens and radishes in 1/3 to 1/2 of the vinaigrette. Place the greens and watermelon on the plate, sprinkle with pickled watermelon rind, and top with the crabmeat.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.