Waves 11 metres high are smashing businesses on Havana's sea side boulevard as Hurricane Irma's powerful winds continue to cause devastation in the Caribbean.
From Cuba to Antigua, Caribbean islanders are counting the cost of Hurricane Irma after the brutal storm left a trail of death, destruction and chaos that may take the tourist-dependent region years to recover from.
The ferocious Category 5 storm killed at least 28 people across the region and left some small islands almost cut off from the world.
Ex-pat billionaires and poor islanders alike were forced to take cover as Irma tore roofs off buildings, flipped cars and killed livestock, raging from the Leeward Islands across Puerto Rico and Hispaniola then into Cuba before turning toward Florida.
Waves of up to 11 metres smashed businesses along the Cuban capital Havana's sea-side drive on Sunday morning. Further east, high winds whipped Varadero, the island's most important tourist resort.
Sea-front hotels were evacuated in Havana and relief workers spent the night rescuing people from homes in the city centre as the sea penetrated to historic depths in the flood-prone area.
President Donald Trump issued on Sunday a disaster declaration for Puerto Rico, where Irma killed at least three people and left hundreds of thousands without power. Trump also expanded federal funds available to the US Virgin Islands.
Further east in the Caribbean, battered islands such as St Martin and Barbuda were taking stock of the damage as people began emerging from shelters to scenes of devastation.
Dutch Prime Minister Mark Rutte said the death toll on the Dutch part of St Martin had risen to four from two and 70 per cent of homes were damaged or destroyed.
Following reports of looting, the Netherlands said it would increase its military presence to 550 soldiers on the island by Monday.
Dutch King Willem-Alexander and Interior Minister Ronald Plasterk are expected to arrive on Sunday.
France, which oversees neighbouring Saint Barthelemy and other half of St Martin, said the police presence on the two islands had been boosted to close to 500.
Irma killed at least 10 people on the two islands, the French government said. France's Caisse Centrale de Reassurance, a state-owned reinsurance group, estimated the cost of Irma at some 1.2 billions euros ($A1.8 billion).
French President Emmanuel Macron is due to visit Saint Martin on Tuesday.
Barbuda, home to some 1800 inhabitants, faces a reconstruction bill of hundreds of millions of dollars after Irma forced the local government to order a total evacuation.
The prime minister of Antigua and Barbuda, Gaston Browne, said Irma caused "absolute devastation" on Barbuda and it was now "barely habitable" with 90 per cent of cars and buildings damaged.
The storm also plunged the British Virgin Islands, an offshore business and legal centre, into turmoil.
Yachts were pilled on top of each other in harbour and many houses in the hillside capital of Road Town on the main island of Tortola were badly damaged.