MD - No rib can withstand it

It is a little significant, that while one sperm whale only fights another sperm whale with his head and jaw, nevertheless, in his conflicts with man, he chiefly and contemptuously uses his tail. In striking at a boat, he swiftly curves away his flukes from it, and the blow is only inflicted by the recoil. If it be made in the unobstructed air, especially if it descend to its mark, the stroke is then simply irresistible. No ribs of man or boat can withstand it. Your only salvation lies in eluding it; but if it comes sideways through the opposing water, then partly owing to the light buoyancy of the whale-boat, and the elasticity of its materials, a cracked rib or a dashed plank or two, a sort of stitch in the side, is generally the most serious result.

- Ch. 86