Art question

Océano Pablo Navarro from Spain writes:

I found the enclosed picture of the Reagans with Prince Charles and Lady Diana in the Yellow Oval Room [actually the West Sitting Hall] and though I've searched all the web, I couldn't know who is the painter of the impressionist beach scene hanging on the wall.
Could you please give me this information?

Update: He got a reply back from Hillary Crehan of the WHHA that...

The painting in the image is entitled: At the Seaside by Edward Potthast. This painting was borrowed from a private collection and is shown hanging in the West Sitting Hall.