Bring water to a boil in a Dutch oven; add potatoes. Cover and cook 10 minutes. Fry bacon until transparent; add onion, and cook until onion is soft and bacon is lightly browned. Add bacon, onion , bacon drippings, fish fillets, and thyme to potatoes. Simmer 10 minutes or until potatoes are tender. Stir in half and half , salt, pepper, simmer 5 minutes. Sprinkle with parsley.