Modern boaters benefit from electronic depth sounders and sonar, but traditional mariners relied on slow speeds, lead lines, dinghies and their eyes to avoid finding the bricks. Lead lines, aka sounding lines, have been widely employed for millennia and are still used by some mariners, Marx included, today. These simple devices consist of a plumb bob, typically lead, with a becket on one end — allowing it to be attached to the sounding line — and a divot at the other end that’s packed with paraffin. A “leadsman” stands forward, next to the headstay, and casts the lead line ahead of his vessel. The sounding line is typically adorned with markers, much like some modern anchor rodes, that indicate how many fathoms of water reside below the water’s surface. Paraffin is added to bring up a bottom sample, allowing sailors to determine the bottom structure (e.g., mud, sand or rock), which can be cross-referenced with their charts.