The £200m vessel, which the public voted to call Boaty McBoatface, was officially named the RRS Sir David Attenborough after the veteran broadcaster.
It was launched for the first time into the River Mersey from the Cammell Laird shipyard in Birkenhead on Sunday.
“It was an extraordinarily emotional moment. I’m surprised myself, really,” Sir David said.
“I’ve never seen a ship of that size get down a slipway and there was something very noble about it and very emotional. Irresistible.”
The largest civilian ship to be built in the UK for 30 years, it will accommodate 60 scientists on research trips to Antarctica when completed.
“To think that it’s going to go to the other end of the globe and do such valuable work and carry so many people from this country who will be working to find out all they can about the working of our planet is a marvellous thought,” Sir David continued.
“I am more honoured than I can say that that wonderful hull has got my name on it.”
Sir David has continued to raise awareness on plastic pollution following the impact his BBC series Blue Planet II had on the issue domestically and internationally.
He has also called on US President Donald Trump to reconsider his threat to withdraw from the Paris Agreement.
Highlighting the importance of the research ship, he said: “The perils facing this planet are far, far greater than they have ever been in its entire history, or at least since the end of the dinosaurs, certainly for the last few million years.
“There’s nothing to compare with the perils we are facing, not only in the scale but in the speed at which they are happening and of course we now know that we are responsible for a lot of these changes that are taking place.
“You have to know what they are before you know how you can fix them so this ship is going to be key to the future salvage of our planet or at least its preservation.”
Sir David pressed the button to launch the vessel with Professor Dame Jane Francis, director of BAS, in front of more than 2,000 shipyard workers, engineers, scientists and other guests including energy minister Claire Perry.
Ms Perry said: “This ship will help us with the tools we need to understand what the world will look like if we let climate change run away and what we need to do to stop it.”
More than 124,000 people voted to name the vessel Boaty McBoatface in a public poll, but the name was vetoed and the ship was instead named after Sir David Attenborough.
A miniature yellow submarine has been named Boaty McBoatface instead in a nod to the public’s choice, which is stored on board the vessel.
Once in the water, after it had been blessed by Bishop of Birkenhead Keith Sinclair, the ship was pulled into the wet basin by tug boats where construction work will continue.