The waves of the ocean, which are caused by the action of the wind, and
which are called secondary or wind waves are of a totally different
character from the tidal wave. The influence of the wind is supposed not
to extend to a greater depth than forty or fifty feet, the deep sea,
though raised in a great mass by the grand tidal movement, being free
from agitation. Wind waves at a distance from the shore are
comparatively low and long, but in shoal water they assume a greater
curvature, and fall on the beach either in gentle ripples or in mighty
breakers, according to the depth of the water and the force of the wind.
The heavy swell which occasionally takes place, called the “ground sea,”
is supposed to originate in distant storms of wind.