A ferry company called today for better regulation of cross-Channel swimmers because the endurance sport is growing so quickly.
DFDS, which runs a service from Dover to Dunkirk, said the rise in the number of those crossing the Channel was raising safety concerns.
The company wants the Maritime and Coastguard Agency (MCA) to take over the running of the swims in the world's busiest shipping lane from two organisations, the Channel Swimming and Piloting Federation (CS&PF) and the Channel Swimming Association.
On the BBC Inside Out programme to be shown tonight, French coastguards also said they would like to see the activity banned.
But the CS&PF said the activity was already well-regulated and safe, with no incidents in 140 years, and that "safety comes first, second and third".
It is thought about 266 swimmers crossed the Channel in the period from late June to early October this year - a large rise on previous years.
The French stopped attempts starting from their coast 17 years ago but allow British swims of the 21 miles separating the two countries to land.
DFDS passenger director Chris Newey said: "We do not want to pour cold water on what can be a fundraising activity.
"However, our first and foremost priority is the health and safety and welfare of those at sea.
"We are concerned these crossings are unregulated and growing at an expedient rate. We would like to see it regulated by the MCA."
Mr Newey said he did not want to suggest the two organisations that run the swims are doing anything wrong but he explained that there is no authority to limit and place restrictions on who can cross the Channel.
"What's to say there could not be another organisation that sets up and then another? We are concerned and we need to have some form of regulatory law," he added.
Honorary secretary of the CS&PF, Michael Oram, said: "Channel swimming is being regulated and for 140 years there have been no incidents - our safety record is exemplary.
"Safety is first, second and third with us."
Mr Oram explained that the Coastguard is informed of the swims and that the boats which escort swimmers have trackers which can be seen by all commercial vessels.
He said the qualification process to attempt a swim is vigorous.
"We are working very closely with the British and French coastguards," he added.
The MCA said in a statement that it has no plans to take over as a regulatory body for the swims.
It also said it was unaware of any plans by the French to ban Channel swims.
A spokesman said: "The waterway is as busy as the M25 in shipping terms so if people want to raise money for their charity we would much rather they did something else.
"But if they do want the challenge then we prefer they use one of the organisations.
"However, in terms of unorthodox crossing in bathtubs and pedalos we take a more robust view - (they) are considered to be highly irresponsible given the volume of traffic through the Dover Strait."
He added: "The numbers of Channel swims is kept under review by the UK and French maritime administrations, and to that end we work closely with the Channel swimming event organisers in the interests of safety."