What Is A Small Craft Advisory?

Staying safe on the water means boaters need to understand different warnings and advisory notices that can help them avoid being on the water in dangerous weather.

One type of warning to learn is the small craft advisory and the flags representing each warning. The Weather Radio broadcast is the best weather-related resource for boaters. NOAA is also a great resource, as it uses a coastal warning display program.

There are several types of flags and colored lights used to display warnings of incoming weather to boaters. So, let's review what those are and what they mean for boat operators.

What Is a Small Craft Advisory?

The National Weather Service (NWS) issues a Small Craft Advisory when winds have reached dangerous speeds. In general, the NWS issues these advisories when sustained winds reach 20 to 33 knots.

Other conditions, such as ice, can also trigger this warning. When these warnings are issued, all boaters should take precautions.

What Boat Size Applies to a Small Craft Advisory?

While the National Weather Service does not explicitly define a "small craft," it's definitely worth paying attention to these advisories when boating. Consider your experience as an operator (or the operator's experience if you aren't driving the boat), the vessel type and size, and water conditions when you see an active advisory.

What Do The Flags Mean?

Each type of warning (or flag) has a different meaning. Knowing the type of advisory and how it could impact your day on the water can help you make a safe decision to change your plans for the day if the conditions are too dangerous to keep yourself and your passengers safe on the water.

In general, the National Weather Service advisories represent the following dangerous conditions — with each advisory indicating increasingly dangerous situations on the water:

• Small Craft Advisory: You'll see this warning when winds reach 18 to 33 knots (or 24 to 38 miles per hour).
• The Gale Warning: This takes things up a notch and lets boaters know that winds have increased to 34 – 47 knots (or 39 to 54 miles per hour).
• A Storm Warning: If you see this flag, wind speeds are greater than 48 knots (or 55 miles per hour).
• Hurricane Warnings: While each previous advisory signals potentially dangerous water conditions, this is an extremely dangerous situation, with winds reaching more than 64 knots (or 74 miles per hour).
• Tropical Storm Warning: This is for winds between 34 – 64 knots associated with a storm system expected to last longer than two hours.
• Special Marine Warning: You'll see this warning with forecasted or observed winds of 34 knots or higher, along with a storm expected to last more than two hours.

Even with the lowest level of these warnings, boaters must pay attention and proceed with caution. If you don't feel comfortable navigating a boat in winds coming in at 18 knots when you see a Small Craft Advisory, it's best to keep your boat on shore and head out on a day with better weather.

Always Put Safety First

Never risk your safety (or anyone else's) for a day on the water if the weather isn't ideal. You never know when something could go wrong in bad weather, and you find yourself and your crew in a boating accident or dealing with being overboard after your boat capsizes.

Learn More About Safe Boating with ilearntoboat

Small Craft Advisories are just one part of understanding how to boat safely! While heeding these warnings can help you keep yourself and others safe, there are other aspects of operating a boat safely that most states require operators tonight before hitting the water.

ilearntoboat can help! Our online, gamified boater education course makes it easy and fun to learn safe boating essentials. In states where our course is available, passing the course and final exam meets the state's requirements for boater education. So, after finishing our course, you can get your boated card and then hit the water safely and legally!

Ready to learn more about staying safe on the water? We cover important information about life jackets, the safety equipment you need on board, what to do if someone falls overboard, how to avoid boating accidents, and more.

Choose the course that applies to your state and start learning!

First published in February 2021. Content most recently reviewed and updated for accuracy and relevancy November 1, 2024.