Lifeguards will not be be manning beaches and people should stay away to help save lives amid the coronavirus pandemic, the Coastguard has warned.
Much of the UK has enjoyed several days of bright sunshine and fine weather at the weekend would usually see crowds flock to seaside resorts.
However, the Coastguard said everyone must follow the government's "very simple" rules and stay at home.
It said it had still been getting calls reporting groups of people on beaches.
Thousands of beachgoers defied the government's social distancing advice last week in scenes that prompted frustration from officials.
Prime Minister Boris Johnson announced stringent new rules on Monday evening meaning people should only leave their homes for limited purposes.
They included being allowed to take daily exercise but the Coastguard said beaches should only be used by those who lived close to them.
Pete Mizen, assistant director for HM Coastguard, said: "The rules are very simple and can be found on the government website. Stay at home.
"The risk of spreading coronavirus is huge and while you might be OK, the person you give it to may not.
"And if you get into trouble and have to call 999 and ask for the Coastguard, you're then putting frontline emergency responders at risk of Covid-19 too.
"At this time of the year the beaches aren't lifeguarded which is a double risk to you and our emergency responders. Help us to help you."
The RNLI confirmed earlier in the week it was "immediately pausing" lifeguard patrols at beaches, and other public organisations have also taken steps to try to deter people from visiting.
Forestry England and the National Trust, as well as some local authority-run country parks, have closed their car parks.
Director General of the National Trust, Hilary McGrady, said there was "so much the public can do at home" and said the organisation would be be "ramping up our efforts to help people connect with nature wherever they are".
"It is really important that we do all we can to discourage travel," she added.