F, Iron keel ballast, important in general stability and self-righting.
She was a self-righting, self-emptying boat, belonging to the Lifeboat Institution.
The self-righting and self-emptying principles he seems not to have thought of; at all events he did not compass them.
The self-emptying principle is quite equal to the self-righting in importance.
The self-righting life-boat of 1901 was a very different boat from that of 1881.
