Tips to Keep Clear of Other Boats

Unlike our roads, our waterways have no painted lines or stoplights to guide us in traffic. So how do we avoid colliding with other boats—especially when they can come from so many different directions?

Well, just like our asphalt highways, there are rules that govern the conduct of boats meeting. Professional mariners must demonstrate their knowledge and understanding of the rules of the nautical road by passing written exams. Most amateur boaters aren’t required to take even the equivalent of Driver’s Ed before they take the helm, but if you don’t learn the basics, you’re taking unnecessary risks.

Rather than hope that the high-speed craft bearing down on your boat has a pro at the helm or is operated by a clairvoyant, it makes sense to drive defensively to avoid collisions. Here are six general rules and concepts that will help you stay out of harm’s way:

  • Always keep a lookout.
  • Travel at a safe speed.
  • When overtaking or passing, the boat being passed has the right-of-way. Keep clear of it.
  • When meeting head-on, keep to the right.
  • When crossing paths, the boat on the right has the right of way. Slow down or change course and permit it to pass.
  • Always use your running lights at night and in times of restricted visibility.

Another key practice to learn is, when you’ve decided you will change course to keep clear, make an early and large course change so your intentions are clear to the other boat captain. Avoid small, incremental or last-minute changes because it may be difficult for the opposing boat to react quickly.

Certain types of boats, like sailboats, generally have the right-of-way over other power boats. This has more to do with their capability to “keep clear” and avoid a collision. We say generally have the right of way, because there are exceptions. Vessels engaged in activities that limit their ability to maneuver have the right-of-way over other vessels. For example, a sailboat has rights over a powerboat, or a large tanker navigating a narrow channel has rights over all small vessels. Even when two powerboats meet, one boat technically has the right-of-way (often referred to as the stand-on vessel) while the other boat is “burdened” to give the right-of-way (often referred to as the “give-way” vessel), assuming that the vessels are within sight of each other.

Another rule to keep in mind is the “tonnage rule.” This is not an actual rule, but generally when the other boat is MUCH larger than yours and could crush you—the prudent move is to stay out of the way!

Signal with your horn

Using horn signals is another easy way to notify other boats of your intent to pass them. Here are some of the most common signals and what they signify:

One short blast: “I intend to leave you on my port side.”
Two short blasts: “I intend to leave you on my starboard side.”
Three short blasts: “I am operating astern propulsion.”
Five or more short blasts: Danger signal.

One prolonged blast is a warning signal given when approaching a blind spot such as a curve in a channel, or when coming out of a slip where your vessel may be obstructed from view.

Make radio contact

If the horn signals don’t seem to work, use your boat’s VHF radio. Hail on channel 16 or 13 to make contact and then switch to a working channel. Give your position in relation to some nearby landmark, not latitude and longitude, as no one has time to plot your position. For example, “This is the blue powerboat exiting the Hog Island Channel at Cleveland Ledge light calling the east-bound tug and tow on my port bow…” Commercial vessels will typically give “security” calls at certain points along their route; simply monitoring the radio will give you an idea of what is going on around you.

Passing in the night

At night, boats have red (port or left side) and green (starboard or right side) sidelights for a reason—so you can determine how you are approaching another boat. One good way to think of this is like traffic lights, if you can see another boat’s red side light, stop or give way. If it’s green, you can keep going. If you are overtaking a boat from astern and can see its white stern light, stay out of the way, regardless of the type of boat. Remember your boat’s “danger zone.” From dead ahead to just behind your starboard beam—yield to boats in this zone.

Avoiding collisions

How do you know if a collision could be coming? When an approaching vessel gets closer but doesn’t change in bearing, you are on a collision course. A steady bearing is easy to see if there’s land in the background; the other boat is holding the exact same position against the land behind it.

Always be courteous and if you do change course to avoid another boat, make the change early and large enough to show the other boat your intentions.