We have all heard the warning from NOAA weather........'small craft
advisory'.

So what exactly is a small craft?

The best I can find on the net is a boat under 65 feet LOA. However, I
would guess anything over 40 feet or so would be able to handle some
*modest* small craft warning seas.

Side note: Conditions that meet a "Small Craft Advisory":
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From http://www.nws.noaa.gov/om/marine/cwd.htm
SMALL CRAFT ADVISORY: To alert mariners to sustained (more than two hours)
weather or sea conditions, either present or forecast, that might be
hazardous to small boats. If a mariner notices a Small Craft Advisory
pennant displayed he should determine immediately the reason by tuning his
radio to the latest marine broadcast. Decision as to the degree of hazard
will be left up to the boatman, based on his experience and size and type of
boat. There is no legal definition of "small craft". The Small Craft
Advisory is an advisory in Coastal Waters and Nearshore forecasts for
sustained winds, frequent gusts, or sea/wave conditions, exceeding defined
thresholds specific to geographic areas. A Small Craft Advisory may also be
issued when sea or lake ice exists that could be hazardous to small boats.

Eastern (ME..SC, Lake Erie, Lake Ontario) - Sustained winds ranging between
25 and 33 knots (except 20 to 25 knots, lower threshold area dependent, to
33 knots for harbors, bays, etc.) and/or seas/waves 5 to 7 feet and greater,
area dependent.

Central (WI..OH) - Sustained winds or frequent gusts between 22 and 33 knots
inclusive, and/or seas/waves greater than 4 feet.

Southern (GA..TX and Caribbean) - Sustained winds of 20 to 33 knots, and/or
forecast seas 7 feet or greater that are/is expected for more than 2 hours.

Western (WA..CA) - Sustained winds of 21 to 33 knots. A Small Craft Advisory
for Hazardous Seas is issued for seas 10 feet or greater.

Alaska (AK) - Sustained winds or frequent gusts of 23 to 33 knots. A small
craft advisory for rough seas may be issued for sea/wave conditions deemed
locally significant, based on customer needs, and should be no lower than 8
feet.

Pacific (HI, Guam, etc) - Sustained winds: northwest through east/southeast
winds of 25 to33 knots for the coastal waters (30 to 33 knots for the
channels between the islands); southeast through west winds of 20 to 33
knots for both coastal waters and channel winds. Swells: open ocean swells
10 feet and greater; swells 6 feet and greater with short periods (6 to 8
seconds); south swell 4 feet and greater with long periods (13 seconds and
greater); north and northeast swells 5 feet and greater with long periods.

"Frequent gusts"are typically long duration conditions (greater than 2
hours).

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