Place the water and tomatoes in large pot and bring to a boil. Whisk in the soup mix until well combined. When the mixture comes to a boil, reduce the heat to low and let it simmer, covered, until the tiny pieces of potatoes in the mix are soft and cooked through, about 25 to 30 minutes.
Meanwhile, place the butter or olive oil in a skillet over medium heat. Add the onion and okra and stir and cook until soft, about 2 to 3 minutes. Add the onion and okra mixture and the bay leaf to the pot with the simmering soup.
Peel and devein the shrimp, and pick over the crab meat for any cartilage and discard.
When the soup has cooked, turn off the heat. Add the shrimp and crab. Stir and bring to a simmer for 2 minutes.
Ladle into serving bowls, and serve with crusty bread.