The RNLI has defended itself against accusations it is encouraging illegal immigration by rescuing people who need help while crossing the English Channel.
The charity said it had a moral and legal duty to help migrants in distress after former UKIP leader Nigel Farage accused volunteers of being a "taxi service for illegal immigration".
Volunteers have reported being heckled as they bring migrants ashore.
But RLNI chief executive Mark Dowie said the sea charity was “doing the right thing” by helping those in need.
“Imagine being out of sight of land, running out of fuel, coming across incredibly busy shipping lanes when you’re frightened and you don’t know which direction you’re going in,” he said.
“That is by anyone’s standards distress. Our role in this is incredibly important: simply to respond to a need to save lives.”
The organisation released dramatic footage showing a rescue in the Channel of a group of migrants on a small boat.
His remarks were made as record numbers of migrants continue to frustrate the government’s plans to make the sea crossing “unviable”.
More than 9,000 migrants have crossed the Channel so far this year, surpassing the total for 2020, when 8,417 people landed on British shores.
On Tuesday, striking photographs showed about 100 abandoned dinghies piled up in rows in a compound in Dover, demonstrating the scale of migrant crossings.
Mr Dowie acknowledged that the migrant crisis was a divisive issue but he said crews were doing humanitarian work.
“These islands have the reputation for doing the right thing and being decent societies, and we should be very proud of the work we’re doing to bring these people home safe,” he said.
He described the poor quality of safety equipment used by migrants to cross the Channel.
“We have seen life jackets made out of lemonade bottles strung together, women and children, young men, old men, with no life jackets, in the middle of nowhere, with ships going past just hundreds of yards away,” he said.
“It’s a very, very frightening environment for those people.”
Officials fear that high numbers of arrivals will continue throughout the summer as the warm weather creates favourable conditions in the Channel.
The UK Home Office previously said migrants were now taking "even longer, riskier journeys" after people smugglers changed their tactics and moved farther east along the French coast.
They send out vessels in waves, with smaller boats sent out first to distract the French authorities. Larger boats then carry more migrants across later.
Nearly 600 people were stopped by border patrols while trying to cross the English Channel in more than a dozen separate incidents on Sunday.