For dressing, in a glass bowl whisk together vinegar, sugar, 1 tsp kosher salt, and black pepper until sugar is dissolved. Let dressing stand while preparing salad.
For salad, cut corn kernels from cobs. In a large bowl toss corn and remaining ingredients except sea salt and arugula leaves.
To serve, transfer salad to large serving bowl. Add the dressing; gently thread in arugula leaves. Taste and adjust seasoning with additional salt, pepper and basil to taste. Serve immediately. (Cucumbers and tomatoes will begin to break down.)
Makes 8 servings