And on the seventh day....

We came to Charlestown, near St Austell, where a Square rigged sailing ship was anchored in the bay.
How I envy the crew! :-)
I checked on Google and found that the sea is this colour due to local china clay (Quartz) deposits, and the ship and harbour are owned by a company called "Square Sails" who's business is to supply ships and harbour scenes to TV and Film Studios.