Eight flights have landed in Cardiff - including long haul planes from the Caribbean and Florida.
Passengers from four easyJet flights have been taken the 177 miles to Gatwick Airport by bus while passengers on British Airways remain in Cardiff after flying from Kingston, St Lucia, Orlando and Cancun.
Flights were halted on Wednesday evening after the two drones were spotted near the airfield, 50 kilometres south of London, triggering the biggest disruption at Gatwick since a volcanic ash cloud in 2010.
News reports more than 100,000 passengers and over 750 flights will be affected and the military has been called in to support local police.
Drones were seen as recently 10pm on Thursday, a Gatwick spokesman said, more than 24 hours after their first sighting.
Prime Minister Theresa May's spokesperson condemned the standoff as "irresponsible and completely unacceptable".
"They require a lot of space and food and changing and all that, and the airport is insane busy so it's challenging", she said by phone among thousands camped in the terminal.
It was reopened at 3am on Thursday, but was shut again 45 minutes later after a further sighting of drones.
"They require a lot of space and food and changing and all that, and the airport is insane busy so it's challenging".
Passengers were stranded at Gatwick airport
Aviation minister Baroness Sugg said: "These drones have been flown illegally and the operators, who have acted incredibly irresponsibly, could face up to five years in jail".
"We look forward to accelerating the cooperation between the industry, drone manufacturers and governments to reduce the risks of rogue drone operations", IATA said in a statement.
Police said they believed the actions were deliberate and more than 20 units were searching for the drone operators on Thursday, when the airport had expected to handle around 115,000 passengers.
Grayling temporarily lifted night-flying restrictions at other airports to ease congestion caused by diverted aircraft, Sky News reported.
With an upsurge of public enthusiasm for drones, there has been an increase in near-collisions by unmanned aircraft and commercial jets in recent years.
Air Canada confirmed it does not operate out of the airport. Woodroofe described one of the drones as a heavy industrial drone.
"We also have the helicopter up in the air but the police advice is that it would be unsafe to seek to shoot the drone down because of what may happen to the stray bullets", Woodroofe said.
Under a new British law, drones can not be flown near aircraft or within a kilometre of an airport, or at an altitude of over 400 feet (122 metres).
"But we are working up contingency plans all the way through to no flights tomorrow".
Passengers took to Twitter to share their stories.