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What Should You Do to Avoid Colliding With Another Boat? – Essential Rules and Tips

Fact checked by William Hart

what should you do to avoid colliding with another boat

What should you do to avoid colliding with another boat? What are the best ways to eliminate boat accidents?

In 2020, the US Coast Guard counted 5,626 boat accidents that involved 3,191 injuries and more than $60 million in property damage. Many of these accidents could have been prevented if boaters strictly followed the marine rules. We’re glad you spend time searching for safety tips before taking the wheel.

Above all, you need to know three basic rules. When two vessels intersect, the one approaching from its starboard side must give way. When one vessel overtakes another, it can pass by either side, but it must display a sound signal to tell which side. When two boats meet head-on, they must pass portside to portside.

We’ll start by explaining the principles, then offer ten more tips from experienced boaters. The water will be hectic and chaotic if boaters fail to obey the rules. So, dive in!

Table of Contents

Understand Boating Rules


Like laws on road traffic, marine rules are based on boat position, direction, and priority. You should acknowledge these basic terms:

  • Vessel: A watercraft or object used as transportation on water, including power-driven vehicles, sailboats, and paddleboards.
  • Stand-on vessel: The vessel that should maintain its course and speed.
  • Give-way vessel: The vessel that should take action to avoid collisions.

When the observer looks toward the bow:

  • The left side of the boat is the port side.
  • The right side is the starboard side.
  • The rear part is the stern.

When two boats meet, three scenarios might occur: they intersect, overtake one another, or meet head-on. If your vessel intersects with another when driving straight, these two rules apply:

  • You are the stand-on vessel if you approach the other from your port side. Keep your course.
  • You are the give-way vessel if you approach the other from your starboard side. Maneuver to give the other the right of way.

When you overtake another boat, follow two rules:

  • The other boat is the stand-on vessel. You must take action to avoid it and stay clear of its way.
  • You can overtake on either side. Use one short blast if you intend to pass to the right and two short blasts if you want to pass to the left. The other vessel should also give you a sound signal to communicate understanding.

When your vessel meets head-on with another, two rules apply:

  • The boats must pass portside to portside.
  • Both boats must actively avoid each other.

The road is only in order when everyone agrees to walk on one side. When drivers follow the rules strictly, the traffic stays clear even during crowded hours. But to eliminate boat accidents, more steps should be taken.

Ten More Essential Rules to Avoid Collisions


Rule 1: Maintain a sharp watch

Always stay alert when driving your boat. Watch for other vessels, navigation aids, and upcoming hazards. You can assign someone aboard to be the lookout, especially in fog or at night. Before turning, look ahead, left, right, and left again, ensuring no obstacles are in the way.

Boating under the influence of alcohol (BUI) is a violation of the laws. The US Coast Guard routinely patrols the waterways and can stop your vessel if you appear to be intoxicated. First-time offenders face up to six months in jail, a $1,000 fine, or probation.

You should have a clear and comfortable vision at all times. The sun’s glare on the water is intense during sunset and sunrise hours. Wear good sunglasses and adjust your speed to avoid sudden reactions.

Rule 2: Pay attention to navigation aids

These visible, audible, or electronic signals help you navigate your course in the vast sea. Understanding them will keep you from colliding with other vessels, particularly in bad weather conditions. Heed signals like lights, day beacons, fog signals, lateral marks (they indicate the edge of a channel), and isolated danger marks.

Rule 3: Steer clear of floating debris

Climate change is affecting us all. In 2020, the Michigan government pointed out that the state was suffering from high water levels, erosions, and storms. They cause a significant amount of floating debris and limited visibility of inland structures. Read the state’s article here.

Be aware of lurking dangers, either floating on the surface or submerged under the water (e.g., wooden docks, stairs, trees, decks, nails, screws, rocks, shattered boards, branches, and other natural debris).

Rule 4: Avoid designated shipping lanes

Always check the chart before navigating an area. The map symbol of a designated shipping lane is a magenta swath. Cargo ships only travel in their lanes and smaller boats must give them the right of way.

Use the following rules if you have to travel in the lanes:

  • Keep to the outer edge of the channel.
  • Cross the channel 90 degree behind a ship. Do so only when it is clear and safe.
  • Turn on the VHF radio to stay updated with local traffic information.

Rule 5: Keep the VHF radio on

When you’re moving, the VHF radio should stay on constantly. Large ships can have a blind spot that extends several miles due to their bows and cargos. Marine signals won’t help as they might not see you at all. Instead, communicate via VHF radio.

  • Turn on your VHF unit and adjust the squelch until you find an open channel (channels 68, 69, 71, 72, and 78A).
  • Perform a radio check.
  • Wait for replies from other boaters to confirm that they have heard your transmission.

In case of an emergency, tune into channel 16 (the channel of the US Coast Guard) and ask for help. You can find detailed instructions in this video:

Rule 6: Show correct navigation lights

In times of reduced visibility, navigation lights are essential to keep you and your vessel safe. The signals allow you to see nearby vessels and them to see you. At night, keep a sharp watch for recreational boats in your area.

You should turn on the running lights when moving. Mooring in designated areas doesn’t require a signal light, but anchoring in other areas requires an all-around white light.

Rule 7: Notice the limited speed

Vehicles should always navigate in a safe manner. The US Coast Guard can stop your vessel if you exceed the speed limit. Keep in mind the rules:

  • Slow down in no-wake zones and low visibility areas (e.g., rain, fog, sun glare).
  • Within 30 meters from the shore, the limited speed is 10km/h. These are the swimming zones.
  • Lower your speed when seeing large ships docking or pulling out. Even when you are out of their way, their prop wash can create turbulence in your vessel.

Rule 8: Use sound signals properly

Not every blast means the same in the marine world. Boaters communicate with a sound signal system. Learning to use it properly will keep you out of trouble:

  • One short blast in one second: I’m passing on the port side.
  • Two short blasts in one second: I’m passing on the starboard side.
  • Three short blasts: I’m backing away from a berth.
  • Five short blasts: Danger or you misunderstand their intentions.
  • One prolonged blast for four to six seconds: You enter or leave a blind turn, obstructed area, or berth.
  • One prolonged blast every two minutes: A large vessel operates in low visibility.

Rule 9: Stay safe when launching and docking

Marinas are usually crowded and bustling. You should maintain a low speed and avoid causing a wake in such areas. Respect others by waiting in line and dock your boat quickly and efficiently. Launching and docking are more challenging in bad weather. So, remain alert to the wind, waves, and vessels’ positions to keep your boat out of harm’s way.

Rule 10: Expect things to go sideways

You should be prepared for when things go sideways, and they will. For example, if the give-way boat doesn’t change its direction according to the rules, the stand-on boat must take action to avoid collisions.

One last tip, carry a radar reflector so you can pick up other vessels’ radars and they can pick up yours. You can also add AIS (Automatic identification system) capability to your radar.


You are making the waterways much safer by educating yourself on boating rules. Every boat owner should understand the ten principles above before standing behind the wheel for the first time. So, feel free to save this article on what should you do to avoid colliding with another boat and reread it. We wish you the safest trips and exciting experiences with your new watercraft.

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