<P> A small craft advisory is a type of warning issued by the National Weather Service in the United States . It is issued when winds have reached, or are expected to reach within 12 hours, a speed marginally less than gale force . A Small Craft Advisory may also be issued when sea or lake ice exists that could be hazardous to small boats . </P> <P> The insignia that denotes a small craft advisory is one red, triangular flag (two such flags, one placed above the other, signify a gale warning). </P>

When do they issue a small craft advisory