Swim the English Channel
The English Channel, often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about 560 km (350 mi) long and varies in width from 240 km (150 mi) at its widest to 34 km (21 mi) in the Strait of Dover. It is the smallest of the shallow seas around the continental shelf of Europe, covering an area of some 75,000 km (29,000 sq mi).
Related goals for England: