5. The charts referred to in regulation 4(1)(a) must–
(a)be of such a scale and contain sufficient detail as clearly to show–
(i)all navigational marks which may be used by a ship when navigating the waters which are comprised in the chart,
(ii)all known dangers affecting those waters, and
(iii)information concerning any ships' routeing and ship reporting measures applicable to those waters,
(b)either be published by the Hydrographer of the Navy or, if not so published, be of a similar scale to those so published and contain equivalent detail; and
(c)in all cases, be of the latest obtainable edition and, be–
(i)in the case of charts published by the Hydrographer of the Navy, corrected and kept up to date from the latest relevant obtainable Notices to Mariners and Radio Navigational Warnings, and
(ii)in the case of charts not so published, otherwise adequately corrected and kept up to date.
In paragraph (b) the reference to the Hydrographer of the Navy includes a reference to any authority in any country other than the United Kingdom exercising functions similar to those of the Hydrographer.