What's a Marine Warning (and What to Do if You See One)

March 10, 2025

Overhead view of a boat moving quickly on dark water, what's a marine warning concept.

What's a marine warning? It's something every boat operator should know and understand to stay safe and protect others on the water. You don't want to put yourself, your boat, and other people at risk by boating in dangerous weather conditions.

Fortunately, you can protect yourself and others by understanding marine warnings and how you might want to change your plans due to one. Like having life jackets and knowing the basics of navigation, recognizing marine warnings can help keep you safe.

Here's what you need to know!

A boat heading toward a dark cloud, caught in severe weather while boating concept.

So, What's a Marine Warning?

The National Weather Service issues Marine Warnings to alert mariners of imminent or occurring hazardous weather conditions. There are several types of standard marine warnings.

These are:

Small Craft Advisory
Gale Warning
Storm Warning
Special Marine Warning

Small Craft Advisory

This advisory indicates conditions that may be hazardous to smaller vessels, such as the ones most people use for recreational activities like fishing or pulling a waterskier.

What is "small?" If you've brought your boat to the water on a trailer behind your vehicle, it's probably considered a small craft.

Gale Warning

This warning indicates that winds of 34 to 40 knots are expected. That's enough wind to cause high waves, choppy seas, and even blow a smaller boat off course.

Storm Warning

Winds over 48 knots are in the forecast if you're notified of a storm warning. When winds are that high, they can create serious hazards for small and medium-sized vessels.

Trying to operate a boat in these conditions could result in capsizing, taking on water, a person falling overboard, or other serious risks.

Special Marine Warning

Special marine warnings are alerts based on short-term hazardous conditions, such as sudden squalls or thunderstorms. These warnings may occur throughout the day, even if the weather was clear earlier.

Because weather conditions can change rapidly, it's always a good idea to stay up-to-date and listen for these warnings.

Warnings, Watches, and Advisories

What are the differences between warnings, watches, and advisories?

A warning is more serious than a watch
A watch is more serious than an advisory

If you hear a warning, the listed conditions are expected soon or occurring. A watch means these conditions could happen, so you want to be aware.

Advisories give you information about what to look out for, but this is more precautionary, and you may not experience any problems.

A boat operator uses a radio while on the boat.

What to Do When You Hear or See a Marine Warning

It's essential to check the marine forecast before heading out on your boat. If a marine warning is issued before your trip, you should cancel or delay your boating adventure for safety.

Sometimes, a marine warning may be issued when you're already on the water. You should have a weather app or marine VHF radio to receive any alerts in real-time.

If you hear an alert for your area, head to the nearest safe harbor or a sheltered location for protection, especially if conditions worsen.

What to Do if You Are Caught in a Severe Storm In Your Boat

If you are caught in a severe storm in your boat, staying calm is essential. Panic can lead to poor decision-making and increase your risk of an accident or injury.

Additionally, make sure you use safety gear. All passengers should wear life jackets until the storm has passed, even if they're strong swimmers. You'll also want to use your kill switch lanyard to avoid losing control of the boat if you're thrown overboard.

Reducing your speed is another way to protect yourself when caught in a storm. You need enough speed to steer, but going too fast can make it harder to avoid large waves or change course when needed.

Position your boat to face waves at a 45-degree angle to reduce the risk of capsizing, and avoid heading directly into or parallel to waves. This gives your boat the best chance of successfully moving through bad weather and rough waters. Don't forget to secure loose items on your boat, as well, to prevent objects from becoming projectiles.

Turn the Lights On

Even in daylight, turn on your navigation lights. Storms can make it much harder for other vessels to see you, and you want to increase your visibility to other boats and rescue teams. Keeping your lights on and your communication open makes it easier for help to find you.

Use your VHF radio to alert the Coast Guard or nearby vessels if you find yourself in distress. Provide your position and situation clearly, and wait for rescue.

Close-up of a boater using a lanyard kill switch while operating a boat. — *Lanyard kill switch connected to boater and helm*

Preventive Measures for Boaters

Preventive measures can reduce risk and increase your peace of mind while on the water.

Before you head out, make sure you:

Equip your boat with a VHF radio, GPS or nautical chart, and emergency supplies such as flares, whistles, and a first aid kit.
Undergo basic weather training to interpret forecasts and warnings.
Develop a storm action plan with your crew or passengers.
Know how to use Channel 16 on your VHF radio to call for help.
Share your float plan with someone onshore so they know when and where to expect you.

These measures can make your day on the water safer and help you have more fun while keeping you aware and prepared if the weather changes.

Remember: Preparation and situational awareness are the best defenses if you're caught in severe weather while boating. Acting quickly and decisively when a marine warning is issued can save lives and property.

A man smiles while holding a boater education card and wearing a life jacket.

Boater Education Helps You Know What to Do When Caught in Severe Weather While Boating

So, what's a marine warning? It's something every boater should recognize and respond to appropriately to stay safe when the weather isn't ideal.

One of the best ways to be prepared if bad weather comes along while you're on a boat is to take a boat education course. You'll learn about marine warnings, proper navigation, preparedness, and other essentials for a safer boating experience.

Boat-Ed offers online courses approved by your state to help you learn everything you need to know for safe boating. As you think about your next boating adventure, make sure you've taken your course, passed the exam, and received your boater education card to boat safely and legally this season!