High tides and strong winds have caused extensive flooding and authorities warned sightseers that they were putting their lives at risk.
Severe flood warnings indicating there is "danger to life" were declared for the southwest English counties of Gloucestershire and Dorset, and for Wales.
Northern Ireland capital Belfast avoided the serious flooding that residents had feared after a tidal surge failed to breach flood defences.
Walls of sandbanks were built in the densely packed residential area of Sydenham in the east of the city and on land around the docks on the opposite side of the shore.
In the southwest English counties, coastal towns in Cornwall and Devon experienced flooding but officials said it was not as bad as feared.