Combine potatoes and water in a medium-size microwavable bowl; cover with plastic wrap. Microwave on HIGH until tender and a knife can be inserted easily in center of potatoes, about 5 minutes. Drain and let stand 5 minutes.
Preheat a grill to medium (400°F to 450°F). Cut 12 (12-inch) square pieces of heavy-duty aluminum foil. Place 6 squares of the foil in a single layer on work surface. Divide potato wedges and corn evenly among foil sheets. Top each with 4 clams, 4 mussels, 1 lobster tail and lemon wedges. Dollop each with about 1-2 tablespoons of Casco Baby Herb Garlic butter. Top each with a couple thyme sprigs, and sprinkle each with 1 teaspoon of HFM's SoFISHticated All-Purpose Seasoning. Place 1 foil square on top of each mixture and crimp all sides to seal tightly.
Grill the tin foil packets, covered, until lobster tails are cooked through and clams are opened, approximately 15 minutes, rotating packets on grill halfway through cooking time. Serve with grilled French bread.