Powerboaters: Have you ever waved at a sailboat crew and gotten stony silence - or worse - in return?

It is not because sailors are snobbish. Many of them view powerboats as a threat, and many powerboaters seem to have no idea of why those rag-pickers are complaining.

Here, in the interest of better understanding, Mad Mariner presents some questions and answers about how sailboats work and what powerboaters need to know to improve relations between the two sides.GLEN JUSTICEAll boaters are responsible for the problems or damage caused by their wake.

Q. Do sailboats really have the right-of-way?

A. Yes—but not always. Generally speaking, if you’re driving a powerboat, you do need to steer clear of sailboats when they’re under sail. But there are three instances in which sailboats do not enjoy any special privileges.

First is when a sailboat is being propelled by an auxiliary engine; in that case, it’s classified as another powerboat, and both you and the sailboat captain must follow standard procedures for two powerboats approaching one another.

Second is when a sailboat is being overtaken by another boat. In that case, the sailboat must maintain its course and speed until the other boat has passed—and it doesn’t matter whether the boat doing the passing is a powerboat or sailboat.

Finally, when a sailboat is approaching a vessel that is constrained by its draft or is confined to a narrow channel—such as a deep-draft merchant ship operating in a designated shipping lane—the sailboat must yield, even if it’s operating under sail.

Q. How can you tell whether a sailboat is operating under sail or being propelled by an auxiliary engine?

A. First, look at the sails and the behavior of the boat. If the sails are filled and puffing out, if the boat is heeled over, and if it isn’t sailing into the wind, it’s very likely under sail. If the sails are flapping or sagging, the mast is vertical, and the bilge-pump overflow pipe is emitting a stream of water, it’s probably being propelled by its engine. If the sailboat is heading into the wind for more than a few seconds, it’s most likely operating under power; sailboats can’t sail directly into the wind. Finally, if the sailboat is moving steadily and has no sails up at all, it’s—well, you probably can guess that one.GLEN JUSTICEInsensitive powerboaters blast by, leaving large wake that can cause problems for sailors. The result is that some sailors see powerboats as a threat.

Q. Why do sailboats rate such special privileges?

A. Coast Guard navigation rules require vessels that are better able to control their movements to yield the right-of-way to those less able.

Sailboats are, to a large degree, at the mercy of the wind. They can’t sail directly into the wind, and they can’t slow quickly the way powerboats can. They also tend to have deeper keels than powerboats do, so they can’t maneuver into shallow water.

That same pecking order—in which easy-to-maneuver vessels must yield the right-of-way to those that can’t move about as freely—requires that sailboats yield to big ships, and that both powerboats and sailboats stay out of the way of trawlers deploying large fishing-nets. (Note that this privilege applies only to commercial boats streaming large nets, not to pleasure craft that carry good old boys and fishing-poles.) Other privileged vessels include those that are confined to shipping channels; restricted in their ability to maneuver, such as dredges; and vessels “not under command”—that is, no longer able to steer.

Q. Sailboats often seem to change course without warning and sail right in front of my boat. Why do they do that?

A. Since sailboats can’t sail directly into the wind, they sometimes must try to move forward by tacking—following a zig-zag course in which they first steer 45 or 50 degrees off the wind in one direction and then shift to 45 or 50 degrees in the other direction. This works fine until the sailboat, which often has a fairly deep keel, approaches the side of a channel and has to change course or else run aground. When that happens, the sailor will tack quickly and turn 90 or 100 degrees in the other direction, surprising powerboaters who aren’t expecting such maneuvers. The sailboat can’t help it. Unlike a powerboat, it can’t slow or stop to avoid the shoal, and it can’t easily just steer around it.