It is lucky for us, in our endeavours to distinguish truth from falsehood, that activities at sea have been scrupulously recorded over the centuries, in insurance records, newspaper accounts and, not least, in ships’ log books. The term log-book has an interesting derivation in itself. An early form of measuring a ship’s progress was by casting overboard a wooden board (the log) with a string attached. The rate at which the string was paid out as the ship moved away from the stationary log was measured by counting how long it took between knots n the string. These measurements were later transcribed into a book. Hence we get the term ‘log-book’ and also the name ‘knot’ as the unit of speed at sea.