Gather ingredients: shrimp, crab legs, lobster tails, mussels, clams, smoked sausage, corn, potatoes, garlic, onion, lemon, butter, Old Bay seasoning, salt, black pepper, cayenne, and water
Fill a large stockpot with water
Add salt, Old Bay seasoning, garlic, onion, lemon, and optional cayenne to the water
Bring the water to a boil
Add potatoes first and cook until nearly tender
Add corn and sausage and cook until heated through
Add crab legs and lobster tails and cook until hot
Add mussels and clams and cook until shells open
Add shrimp last and cook until pink and opaque
Drain the seafood boil
Melt butter with garlic, lemon juice, and seasoning for dipping
Pour the butter sauce over the boil or serve it on the side
Serve immediately on a large tray or lined table
Discard any unopened mussels or clams after cooking