What is a Small Craft Advisory?

December 20, 2023

A Small Craft Advisory is issued by the National Weather Service (NWS) in the United States as a warning to mariners about hazardous marine weather conditions, including high winds, tall waves, rough seas, heavy rain, thunderstorms and other dangers like sea and lake ice.

Boaters are advised to stay informed about weather conditions and take all necessary precautions whenever a Small Craft Advisory is in effect.

What wind speeds trigger a small craft advisory?

The specific sustained wind speeds triggering this advisory may differ by geographical regions but typically fall between 18 and 33 knots, or 24 to 38 miles per hour.

A Small Craft Advisory also takes wave height into consideration. When waves reach between four and seven feet, an advisory may be issued.

What should mariners do if there is a small craft advisory?

The advisory informs small boat operators of potential dangers. When there is a Small Craft Advisory in effect, you are not prohibited from boating, but you are advised to remain cautious.

Appropriate steps include:

  • Exercising extra vigilance
  • Staying aware of the prevailing weather conditions
  • Implementing safety measures
  • Reconsidering your boating plans altogether.

Safety precautions may also involve remaining in port, adjusting course to avoid risky areas, or preparing yourself with extra on-board safety equipment.

What type of vessel counts as a small craft?

The National Weather Service does not provide a specific definition for a Small Craft. Instead, factors such as the operator’s experience, the type and size of the boat, and the overall condition of the vessel should all be taken into consideration when deciding what to do during a Small Craft Advisory.

Other types of wind warnings

A Small Craft Advisory is just one type of marine forecast. Be mindful of other National Weather Service marine forecasts for boaters that are even more serious:

  • Gale Warning: Winds of 34 to 47 knots, or 39 to 54 miles per hour.
  • Storm Warning: Winds of 18 to 33 knots, or 24 to 38 miles per hour.
  • Hurricane Warning: Winds greater than 64 knots, or 74 miles per hour.
  • Tropical Storm Warning: Current or forecast winds of 34-64 knots.
  • Special Marine Warning: Current or forecast winds of 34 knots or higher, combined with a storm that will last more than two hours.

While the Weather Radio broadcast remains your primary source for weather conditions, NOAA also employs a Coastal Warning Display Program, and a complete list of warnings at nowCOAST online.

Flags and colored lights are sometimes used to alert boaters to storms. If any of these display signals are present, it is strongly recommended to reconsider heading out on the water.

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A Small Vessel Advisory is a cautionary signal that small vessel operators should take seriously. It is always better to prioritize safety and stay on land during any type of weather warning. Be patient so you can enjoy a stress-free day on the water as soon as the weather is back to normal.

In fact, a day spent grounded on shore is the perfect opportunity to improve your knowledge of boating laws and regulations. Drive a Boat USA offers top quality boating safety courses online. Learn all about boating, step by step, and obtain your state-approved boating licence!