Thanks Archimedes for the accurate facts (yes, a lot of boats left the French Atlantic harbours, there was much fog of war during the second half of June 1940) PM Winston Churchill took the right decision to call all of them back, otherwise they would all have been captured - so as a leader he had to save the Army for the future, which might have been very different with 100 or 200,000 soldiers less (I read all his War Memories year ago, 14 books, who did here ?)
Sadly both sides have quite often the wrong perception of the other one, the French considering that the Brits ran away, and the Brits scorning the surrender of the French...
In fact a lot of French evacuated from Dunkirk, or back from Norway, did form in England the nucleus of the Free French Forces, to be reinforced later by men from the Colonies or having escaped through Spain (or the Channel !) Some joined directly the RAF squadrons, like South Africans for example, and others fought in dedicated French units.
As rh200 rightly said, at the end Victory was there.
Some people start those stupid jokes with me being present - CRM apart, it's usually not a good starting point. Have they been at war by the way ? I happened to be.
And remember, without the Channel...