Sometimes, you're faster than the other guy. When it's a pair of pleasure boats operating in open water, this is no big deal. Cross the stern wake as early as possible, leave plenty of room, be mindful of your own wake and give a friendly wave as you pass.
But if you're both headed the same direction along any type of defined channel where there is limited room to maneuver, a speed difference will eventually lead to a more-formal event known as a passing or overtaking situation. And while passing another boat is similar to what happens to cars on the road, there are a few differences. And there are rules.
On canals, some lakes and most rivers, the process of overtaking should be done according to the United States Coast Guard's North American Inland Rules. Boats in coastal and offshore waters will use the International Rules. Differences between these sets of rules lie mainly in the specific signals or language the skippers use to communicate with each other, but the intent is the same: to ensure the safety of all involved.
In any body of water that is considered a navigable waterway, you don't automatically have the right to pass another boat. A boat planning to overtake (pass) is referred to as the "burdened" or "give way" vessel, while the guy up front is considered the "privileged" or "stand on" vessel — he has the right of way. Before overtaking, the burdened vessel is expected to ask — and receive — permission from the boat up ahead.
The privileged skipper can deny the burdened vessel the right to pass. Reason for doing so might include oncoming traffic (there could be a big barge coming around that blind bend), a narrow channel that doesn't leave room for the privileged vessel to maneuver, or a concern that your wake could cause damage to the privileged vessel's cargo or crew — a very real concern with certain types of work barges that are loaded with working machinery.
When small boats pass big ships, it's a good idea for the small-boat skipper to get the attention of the larger vessel and then wait for a "go ahead" acknowledgement. Big boats make big turns, which could force a small boat caught in the middle of a passing maneuver completely out of the channel, or bring it dangerously close to churning propellers or powerful side thrusters.
When it's one pleasure boat passing another pleasure boat of similar size, the passing rules are not always observed, but they should be. At a minimum, there are some common courtesies that should be observed.
As the passing vessel, your goal should be passing with the smallest possible wake. When passing in a controlled speed or no-wake zone, extra caution will be needed to prevent throwing a big wake that could dislodge dishes or topple passengers. But, at higher speeds, judgment should come into play. Sometimes slowing down might actually produce a larger wake and prolong the damaging wake. Staying on plane and giving a bit more room might produce much less wake. Also, keep in mind that slowing at the wrong time can plow up an especially large wake as your boat settles off plane.
Experienced skippers will often work together when passing in slow-speed zones. In such cases, the overtaking boat will wait until the boat being overtaken slows to almost idle speed and moves as far to the right of the channel as is safe and practical. This will allow the overtaking boat to pass expediently while still maintaining a proper no-wake speed, and will keep everyone on a friendly, even keel.
Give A Whistle
Though VHF radio is now the accepted means of boat-to-boat communications, passing situations are still governed by sound signals.
Horns have replaced whistles, but the sound patterns — defined as short and prolonged blasts — are still the same. If you tune into VHF radio traffic, you might hear salty, old commercial captains talking to each other in terms of one-whistle or two-whistle passes. This is what they mean.
1 Short Blast: "I intend to pass you on your starboard side." The privileged vessel will signal agreement by responding with 1 short blast.
2 Short Blasts: 2 Short Blasts: "I intend to pass you on your port side." The privileged vessel will signal agreement by responding with 2 short blasts.
2 Prolonged Blasts/2 Short Blasts: "I intend to pass you on your port side." The privileged vessel will signal agreement by responding with 1 prolonged/1 short/1 prolonged/1 short blast.
2 Prolonged Blasts/1 Short: "I intend to pass you on your starboard side." The privileged vessel will signal agreement by responding with 1 prolonged/1 short/1 prolonged/1 short blast.
The U.S. Coast Guard Navigation Rules ("Rules of the Road") are what you'll be judged by in case there's an infraction. Download a free copy at http://www.navcen.uscg.gov/mwv/mwv_files/NR_Files/navrules.pdf.