At least 444 people crossed the Channel on Tuesday, the highest daily figure since the government announced it planned to send some asylum seekers to Rwanda.
As the government fought last-minute legal challenges to stop the first deportation flight leaving on Tuesday, hundreds of people made the dangerous crossing from France.
More than 10,700 people have reached the UK on small boats this year, according to data compiled and analysed by Sky News.
This is double the number who had reached Britain by the same point last year, figures show.
More crossings are expected on Wednesday as the weather is calm.
Priti Patel, the home secretary, announced the Rwanda policy on 14 April, the day after 651 people crossed the Channel, the highest figure so far this year.
The number of arrivals on Tuesday is the highest since 14 April, when 562 people made the crossing.
Campaigners say the policy is inhumane and Church of England leaders have said it shames Britain, but ministers argue it will deter crossings and “break the business model” of people trafficking gangs.