Spindrift

Spindrift usually refers to spray, particularly to the spray blown from cresting waves during a gale. This spray, which "drifts" in the direction of the gale, is one of the characteristics of a wind speed of 8 Beaufort and higher at sea.

In Great Britain "spindrift" is the telltale sign used by mariners to define a Force 8 (Beaufort Scale) wind (not higher) when observed at sea. See this example of information provided by Lymington Harbour authority, Hampshire, England, UK, explaining the whole scale, the associated wind speeds, and its telltale signs. Text from the site states: