PJM requests an explanation of the difference between "sheets" and "halyards." An excellent question. First, let me say how much I LOVE to teach adults about sailing. All Stay of Execution readers are invited to visit me and come out for a sailing lesson. I love it not only because I love the subject matter and because adults have the attention span and the abstract thinking skills to "get it" quickly (although kids pick up the "feel" and the more instinctive reflexes you need better than adults), but also because I think adults who attempt to learn to sail are courageous and brave. I admire and envy them at the same time -- moving tentatively into a world full of mysterious vocabulary words and invisible forces and unstable surfaces that move around and leave you with bruises and bumps. And we sailors aren't often very good at articulating the information you'll need to get out on a boat and feel useful and acclimated. If we do bother to teach you the name of something it is most likely that we will only teach you one of several existing names for it, and when we next reference the thing we will use an entirely different name than the one we taught you. So anyway, adult learners, you're brave to come aboard, and your courage will be rewarded by a lifetime of great experiences on boats.
"Halyards" and "sheets" are both types of lines. ("Line" is the sailor word for "rope" -- we never say "rope" unless the line being referred to is four inches thick and made of thick brown hempy stuff and connecting a tugboat or something to the dock. Please pay attention to this because we will shake our heads with irritation and correct you every time you mix this one up. Why? Just because.) Both halyards and sheets control the sails. Halyards pull the sails up the mast. Generally, once you pull a sail up, you keep it up there for the duration of your sailing adventure, so you'll encounter halyards at the beginning and the end of the day. Until you've messed around with the halyards and gotten the sails up, there's no need to bother with sheets.
But once the halyards have pulled the sails up, you tend to coil them up (to make sure if you need to let the sails down in a hurry the line will run smoothly and not be tangled up) and forget about them while you're sailing. That's when you use the sheets. The sheets adjust the angle of the sails to the wind. If you let them all the way out the sail will flap around uselessly like a flag on a flagpole. By pulling the sheet, you give the sail a certain shape, and it is that shape that creates the lift effect that can make the boat go forward. (If we were at lunch together I would be furiously drawing diagrams on napkins right now). The sheets are where it's at while you're sailing.