The ship, Saga’s second new-build, joins Spirit of Adventure in Tilbury.
There, Adventure will lay up for the winter ahead of its inaugural cruise departing 5 February 2021 sailing to the Canary Islands.
Saga took delivery of Spirit of Adventure from shipbuilder Meyer Werft on 29 September.
The ship has 554 all-balcony cabins, and has a total capacity of 999 passengers.
Nigel Blanks, managing director of Saga Cruises, said Discovery and now Adventure had allowed the line to create a "boutique cruising experience".
"With Spirit of Adventure joining our fleet, we now have more choice for our guests with two unique ships," said Blanks.
He added Saga had also been working on new Covid procedures ahead of a resumption of cruising, which include sailing at reduced capacity, pre-departure testing, and increased medical staff and facilities onboard.
