Analysis of information sources in references of the Wikipedia article "Swordfish" in English language version.
The 60 mph figure listed for the swordfish is based on a corrupted version of calculations made by Sir James Gray to estimate the impact speed necessary for a hypothetical 600 lb [270 kg] swordfish to embed its sword 3 feet [90 cm] in the timbers of ships, as has been known to occur; the figure seems to have entered the literature without question.