Domestic cruises this summer will be restricted to as little as a fifth of normal capacity, according to rules announced by the Department for Transport.
A dozen cruise lines will operate voyages around the coast of Britain this summer, with many reporting exceptional demand amid uncertainty over restrictions on foreign travel.
Cruises are currently banned in the UK due to the pandemic but will be permitted in England under the next step of Prime Minister Boris Johnson's road map for easing rules, which is planned for May 17.
But the DfT said ships operating in England will only be allowed to carry up to 1,000 passengers - or 50 per cent of their capacity if that is lower.