What Is a Small Craft Advisory?


Though the Weather Radio broadcast is your best resource for weather conditions, NOAA also uses a Coastal Warning Display Program at select small boat stations.

The following flags and colored lights are displayed to warn boaters of storms. Any of these display signals should make you think twice about heading out on the water.

What Is a Small Craft Advisory?

A Small Craft Advisory is issued by the National Weather Service as a warning when winds have reached dangerous speeds. Sustained wind speeds that govern the issuance of a Small Craft Advisory vary depending on geographical areas, but are generally between 20 and 33 knots. It can also be issued for other hazardous conditions such as sea and lake ice. All boaters should take appropriate precautions during a Small Craft Advisory.

Small Craft Advisory: Boat Size

The National Weather Service does not specifically define a Small Craft with regards to the size of the boat. Experience of the operator, type and size of the boat and the overall condition of the boat are all factors that should be considered.

Small craft advisory flags

Small Craft Advisory

Winds of 18 to 33 knots, or 24 to 38 miles per hour.

Gale warning boating flags

Gale Warning

Winds of 34 to 47 knots, or 39 to 54 miles per hour.

Storm warning boating flags

Storm Warning

Winds greater than 48 knots, or 55 miles per hour.

Hurricane warning boating flags

Hurricane Warning

Winds greater than 64 knots, or 74 miles per hour.

You'll also want to pay close attention to tropical storm warnings, which are given whenever there are observed or forecast winds of 34 to 64 knots. Special marine warnings are broadcast when there are observed or forecast winds of 34 knots or greater, and the winds are part of a storm system that is expected to last longer than 2 hours.

Other Warnings to be Wary of:

Tropical Storm

Observed or forecast winds of 34-64 knots.

Special Marine

Observed or forecast winds of 34 knots or higher, coupled with a storm to last more than two hours.