In a large, deep pot with a tight-fitting lid, bring 2 inches of water to a boil. When boiling, quickly add the lobsters and cover. Steam for 10 minutes for 1 1/4 pound lobsters, or 11-12 minutes for 1 1/2-2 pound lobsters.
In a small bowl, combine all of the tartar sauce ingredients.
Remove the lobsters from the pot and serve with tartar sauce, melted butter and lemon wedges.