Fill a large pot with water
Add salt, Old Bay seasoning, bay leaves, lemon halves, garlic, and onion
Bring the water to a boil
Add potatoes and cook until almost tender
Add corn and sausage
Cook for a few minutes
Add live or cleaned crabs
Cover and boil until the crabs turn bright red and are cooked through
Drain the boil
Serve with melted butter, lemon wedges, and extra seasoning