Whisk together vinegar, honey, mustard, 1/4 teaspoon salt, and 1/8 teaspoon pepper in a small bowl; slowly whisk in 1/4 cup olive oil. Set aside.
Toss shrimp with garlic and 1 tablespoon olive oil. Sprinkle with remaining 1/4 teaspoon salt and remaining 1/8 teaspoon pepper. Grill over medium-high heat 3 to 5 minutes or until done.
Divide arugula among 4 serving plates; top with tomatoes, watermelon, and onion. Top evenly with shrimp, and drizzle with vinaigrette.
Pour: Carolina Grunner, co-owner of The Wine Room of Forest Hills, a boutique wine shop located in Forest Hills, New York, suggests serving this summery dish with Marchesi di Barolo Gavi Le Lune. â€œIt's a dry, crisp, and refreshing white wine with great acidity, making it a perfect match for the balsamic vinaigrette and the goat cheese,â€� she says.