The listed coordinates are incorrect: the cache is not located in the Bristol Channel! It is, however, hidden somewhere in the photograph below — but it's up to you to work out where.
This puzzle must be solved from home. It is not my intention to send cachers out to scour the coast. Once you have solved this puzzle you will know, without doubt, exactly where to go.
Parking is available at Dunraven Bay, near Southerndown (N 51° 26.770' W 003° 36.320'). Depending on the time of year, there might be a small charge.
Please take care when walking in this area: the coastal paths can be dangerous. There are sheer cliffs, and the path can be slippery, so appropriate footwear is recommended.
The container is a small, lunch-box style plastic container. It is hidden close to the path.
For more information about the area, you might contact the Glamorgan Heritage Coast Centre which is located at Dunraven Bay.