Way Downstream …

       In Calvert County, the late Tom Clancy’s 537-acre Bay-front estate is on the market. Asking price, $6.2 million.

      Peregrine Estate, as the megabucks author of Hunt for the Red October and other best-sellers called it, is a 17,000-square-foot mansion, with a mile of waterfront and its own fossil-filled cliff.

       See panorama of the property set to high-strung music at ­cummingsrealtors.com, the company that would like to sell it to you.

       Features include a three-level elevator and attached four-car garage for your Porsche, Rolls, Jag and Humvee. If you happened to have a few old beaters you can’t part with, there’s also a four-car unattached garage.

        For getting in Jack Ryan-shape, the indoor pool pavilion with retractable roof has a fitness center and, below-grade, there’s a two-lane private gun range. If your dreams are literary, you can write at Clancy’s built-in petrified-wood desk.