Totally aside from its politics, Washington, D.C., has always been a boater-friendly town, located on the banks of the Potomac with first-class marinas on both the Maryland and Virginia sides. Boaters have been sailing up the Potomac from the Chesapeake and beyond ever since the British sent warships up the river in the War of 1812. It’s much more peaceful now, and much more welcoming, particularly with the completion of the $3.6 billion, 24-acre Wharf project along Washington Channel just south of the Mall. The massive Wharf Marina there has more than 300 slips along the development’s mile-long promenade that…