Sadko in the underwater kingdom Ilya Repin (1844-1930)

The picture has something of this: underwater, fish, water, invertebrate, people, ocean, water sports, reef, coral, swimming, sea, wildlife, aquarium, kelp, environment, diving, recreation, exploration.
Perhaps it’s a painting of a man and a woman sitting next to each other in front of a seaweed and coral reef with a fish in the water.