In a large stockpot over medium-high heat, combine the clams and water and bring to a simmer. Cover and steam until the clams open, about 10 minutes.
Using a slotted spoon, transfer the clams to a work surface and remove the meat from the open shells, discarding any shells that did not open. Coarsely chop the meat and reserve. Strain the stock through a fine mesh strainer lined with cheesecloth into a large bowl. Add water if needed to make 6 cups of stock. Reserve.
Rinse and dry the stockpot and place over medium heat. Add the bacon and cook until the fat is rendered and the bacon is crisp, about 8 to 10 minutes. Transfer onto paper towels to drain.
Increase the heat to medium-high and add the butter, thyme, bay leaf, onion and celery. Season to taste with salt and pepper. Cook, stirring occasionally, until the vegetables soften, about 8 to 10 minutes. Stir in the flour and cook for 2 more minutes. Slowly stir in the stock. Add the potatoes and bring to a boil. Decrease the heat to medium and cook until the potatoes are tender, about 20 minutes.
Add the clam meat and cream and cook until warmed through, about 5 minutes. Discard the thyme and bay leaf. Stir in the sherry and season with additional salt and pepper if needed. Serve in bowls topped with the bacon and chives.
Content courtesy of Oceania Cruises