I do note that the "winter menu" could be a prologue to the next summer menu: handhelds and bar food. "What do those non fish boat captains need with menus and white tablecloths?" "Shut up and pour." Not surprising that the Marlin Club isn't serving in the dining room on Sunday for "the winter months". In season, it was hardly occupied and Thursdays were often not better. 

It never takes more than two years to kill off a successful restaurant and it's not particularly difficult to accomplish.  Take it from a bankruptcy trustee.