The new-look Admiralty chart is no longer novel; the first metric chart was in fact published ten years ago and there are now over 700 metric charts in our standard series, representing over 20 per cent of the total currently in publication. Their impact is disproportionate to their numbers however, since many metric charts figure among those most used, and there is now about a one-in-three chance that any Admiralty chart being employed is a metric one. Popular charts tend to be much-corrected charts and in fact a third of the new editions and a third of the paste-on blocks that we issued last year were to metric charts. Moreover, we now publish a hundred new charts a year and hope that this figure will be maintained.