spar buoy

A glance in the direction indicated showed the boys an object like a spar buoy apparently standing upright in the water.

He had paid out nearly two miles of cord, when the top kite, a little two-footer, stood straight over the spar buoy in Newark Bay.

The spar buoy (fig. 50) may be adopted for situations where strong tides or currents prevail.

There's a black-and-red spar buoy there, as you see, but we haven't sighted it.