Like the coastal mist, suspicion and uncertainty lingered on both sides, but some sort of statement of principles is likely to be issued today by Tony Blair, President Jacques Chirac and the French Prime Minister, Lionel Jospin.
However vague the final language - and vague it is likely to be - the occasion can reasonably claim to be historic.
French officials say the preparatory talks have been the most substantial and innovative on a large European issue between London and Paris since the dawn of France's Fifth Republic in 1958: in other words since President Charles de Gaulle's "non" to British membership of what was then theCommon Market.
This is the 21st annual Anglo-French summit, but the first in which the two governments have sought - notwithstanding the anti-European thunder in the British press - to act as a battering ram for the creation of a new EU policy.
There has been much talk of Franco-German axes and Anglo-Franco-German triangles but this is the first time that London and Paris have conspired, in the Franco-German manner, to push EU powers into a significant new area.
Mr Blair was meeting President Chirac tete-a-tete last night, followed by dinner with Mr Jospin. All three will come together for a joint press conference this morning.
There is other business on the table: the reform of the EU budget and farm policy; German ideas for the harmonisation of VAT and corporation taxes; the enlargement of the EU to the east and Western policy in Iraq and Kosovo. There will also be meetings between the British and French Foreign, Defence, Finance, Transport and European ministers.
But the centrepiece - fittingly in a town that has been at the heart of Anglo-French enmity and alliance for centuries - is defence policy.
Should the EU have one? If so, what should its scope and powers be; and how can it be called into being without weakening Nato and encouraging future American administrations to dilute US commitment to the defence of Europe?
St Malo was for centuries one of the principal ports from which French corsairs raided British shipping; it was blockaded for years by the British fleet during the Napoleonic wars and it was flattened by American and British bombers, in the cause of French liberation, in August 1944.
The new defence relationship between London and Paris was symbolised yesterday by the presence in the inner harbour of the destroyer HMS Birmingham, moored alongside the French warship, Tourville. The Secretary of State for Defence, George Roberston and his French colleague, Alain Richard, are due to sign a letter of intent on military co-operation aboard the Royal Navy vessel today.
But how can such partnerships be handled at the highest level? The two countries are by far the greatest military powers on the Continent, east of Russia. Each has become frustrated - Britain from within Nato, France from outside - with their inability to make that strength count in local but poisonous conflicts in which the US refuses to get involved.
The central aim of the summit is to produce a statement of principles that would square both British and French anxieties and, it is hoped, appeal to other European countries and the US at the Nato summit next spring.
Britain has agreed for the first time that defence policy can be decided at EU level. The principal difficulty is what to do with the Western European Union, the existing, ineffectual, European defence arm, suspended somewhere between Nato and the EU.
Britain would like the WEU's forces to be given to Nato and its decision- making capacity to go to the EU. The French want the WEU to be swallowed up by the EU wholesale and its logistics, satellite and transport capacity increased.
Officials were working last night on compromise wordings between these positions, which Mr Blair, Mr Chirac and Mr Jospin could sign today.Reuse content