CARDIFF BAY

Depths within Cardiff Bay are referred to the normal water level which is 4·0
metres above Ordnance Datum. This level is not guaranteed and variations may
occur for operational reasons. For the latest information contact the Cardiff
Harbour Authority. Special buoys are positioned around the bay to monitor water
quality. These buoys are not for navigation and should be given a wide berth.
A 5 knot speed limit zone within the harbour is marked by lit yellow buoys.