Sailing has a rich history. From its early incarnation as man’s primary mode of transportation to a competitive sport, sailing has a wide appeal. Before simply diving into sailing, however, take the time to learn at least a little about your surroundings on a sailboat. You may find it extremely difficult to get the gist of the pieces of the sail and sailboat. According to North Sails, the sail depth plays an important role in performance. The more sail you have, the more wind your boat can capture, increasing your speed.
Locate the head rope on the sail. The head rope is a part of the boltrope -- a precautionary seam sewn onto the upper edge of the sail to prevent tearing.
Locate the foot rope, sewn onto the lower edge of the sail.
Measure the distance between the head rope and the foot rope with your tape measure to determine your sail's depth.