The beaches of Calais and Gravelines near Dunkirk have been the main small boat launch sites since the number of crossings started to increase from 2018.
But the recent use of Belgium’s coastline has led authorities to step up land and sea patrols, as well as from the air with the deployment of the Frontex aircraft.
David Raynes, who was part of HM Customs and Excise National Investigation Service, told BBC South East he was not surprised by the latest tactics.
“Thwarted smugglers constantly try new methods and routes,” he said.
“The Belgian local administration need to be aware, if they let the smugglers settle to a new pattern, there will quickly develop camps and infrastructure similar to those in Calais.
“Prevention now, will be much cheaper than future cure,” he added.
A Belgian Federal Police spokesperson said: “Crossing the Channel in a small boat is extremely dangerous and our goal is, of course, to stop all attempts to do so.”
They added that information was exchanged daily with the French and British police.