The waters for French fishermen are being stirred up by uncertainty of what will happen if Britain leaves the EU without a deal on October 31 and their boats barred from British waters.
A no-deal Brexit would likely end access for French boats to British waters and, in France, fishing industry players fear this will not just increase tensions with rivals across the Channel but between themselves.
Sophie Leroy, whose Armement Cherbourgeois company operates three fishing vessels off the northwest coast of France, says there have been almost daily checks of their boats by the British authorities.
Earlier this month, her boats were stopped for what she described as an interminable set of checks 21 miles off the English coast.
Her boats were also surrounded by 15 British fishing vessels, she said.
"And they were saying, 'We are going to do the same as what the French did to us last year'."
"So, inevitably, there will be conflicts between fishermen, between inshore fishing, between gill-netters, between offshore trawlers who are going to come in closer to the coast."