Cook the pasta, drain it, rinse it with water, and set it aside.
Cut lobster, crab, and shrimp meat into pieces.
Season the seafood meat.
Melt butter in a pan over medium heat.
Add water, flour, cream, and milk to the pan, then stir until the roux turns smooth.
Melt butter in a pot, add the roux, and cook for five minutes.
Add cheese to the roux and season with pepper and salt.
Preheat the oven to 350°F.
Mix seafood meat, pasta, and breadcrumbs or crackers.
Add cheese sauce and seafood meat to the baking dish in different layers.
Sprinkle shredded cheese on top.
Bake the mac and cheese for 30 minutes in the oven.
Enjoy your food.