The tidal surge in Skegness has reached its highest point and water levels are now falling around the town.
High tide was shortly after 7.30pm.
A large number of people gathered on Tower Esplanade to witness the dangerous spectacle, sparking frequent efforts by police to move the public further back to safety.
At its highest point the water was spilling into the boating lake and well up the road towards the Clock Tower.
The lagoon in front of the main car park was also full as the tide swept over the dunes.
However, the threat has not passed. The high tide continues to work its way down the coast towards Boston - where there are already reports of flooding.
And police have reported that the Gibraltar Point Nature Reserve just south of Skegness may have been “breached”.
They are advising people to avoid the area.
Meanwhile, the force has reitereated earlier warnings to the public to be prepared for the worst.
A spokesperson said: “There have been higher than expected tides experienced in Newcastle and the Humber areas and coastal areas of Lincolnshire are now at serious risk.
“There is life-threatening risk to residents in certain parts of Boston. Flooding has already been reported in some streets in Boston as the Haven has risen substantially.
“A number of roads are closed in Boston: High street, Fydell Cresent at George Street junction and Bank Street.
“If you live in the affected areas, you are at considerable risk. Please move to a place of safety immediately.
“We’ve had reports of some people ignoring the advice of the emergency services on the ground and venturing out to take pictures etc. This is very dangerous. Please remain where you are safe.
“Buses for evacuation to the PRSA are now from Asda and Wide BarGate (Post Office). We are no longer picking up from the Bus Station.”