Sailors are famous for their tall tales, and have long entertained the world with stories of ghost ships, sea monsters, mermaids and other wonders. Scientists are cautious about accepting such anecdotal evidence, and so accounts of giant waves taller than the mainmast (see FT177:40–41) tended to be taken with a pinch of sea salt. Experience shows that waves which look like 12-footers are often 6ft (1.8m) at most – cool judgement is difficult to exercise when your life is at stake. Victorian oceanographers calculated that any wave of more than 60ft (18m) would collapse under its own weight, and concluded that reports of anything larger must be exaggerations.