Volume Eleven - Pre-Victorian to the Present Day - some more aspects - Handbook to Penarth Dock & Ely Tidal Harbour - 1904 . . .

The depth of water on the Dock sill is 36ft. ordinary spring, and 26ft. ordinary neap tides. The entrance channel is kept constantly dredged, and is deeper by several feet than the Dock sill, so that vessels enter deep water immediately on leaving the Dock. Penarth has, in fact, one of the deepest entrances in the Channel, in proof of which may be stated that the undermentioned vessels of large size and capacity have left the Dock fully laden without delay and with perfect safety.