The situation off the Channel Island of Jersey is a "very bad look" for the allied nations of the UK and France, a professor has said.
Professor Michael Clarke, former Director of RUSI, told Forces News it appears Britain "felt that it needed to make a strong gesture" to France with the deployment of two Royal Navy vessels to the scene.
Prof Clarke added: "We have to be careful – we don't want any accidents, and we don't want to escalate the situation which has got to be solved by negotiation.
"We've got ships that are far too big for this issue manoeuvring in the area to show presence."
As the UK and France are NATO allies, and are also partners in a bi-lateral treaty on defence co-operation, the professor said the current situation shows neither nation in a positive light.
"It's a very bad look for allies that work together in other respects," Prof Clarke said.
"The Franco-British defence relationship hasn't been terribly good recently.
Watch: A former Royal Navy commander on what it's like to be deployed in this type of role.
"The idea that we are now competing on fisheries protection with our military assets is very poor.
"This whole situation needs to be defused very quickly, this should be about negotiation not gunboat diplomacy on both sides of the Channel."
He continued: "This issue for these offshore patrol vessels is that they're there to make arrests at sea, they're not there to fight wars or to fight other ships."
Former Royal Navy commander Tom Sharpe, who was captain of HMS Lindisfarne from 1999 to 2000 and involved in fishery protection during that time, said the role is "very, very common" and "an ancient naval task that happens every day".
"Militarily, the ships will be very calm about this.
"That's these vessels' core roles... one of their prime functions is to do fishery protection.
"Just the interaction that them being sent there has already generated [dialogue] between the two governments."
The weapons on Tamar and Severn are covered up, something the former commander said is deliberate as the task is "non-escalatory."
"They're on fish duties, as we call it, weapons are not required," he added.