(CNN) Scores of foreign experts flew into a remote area of northern Thailand to help the Thai Navy SEALs execute a rescue mission that had been called urgent, risky and dangerous.
Divers, engineers, medics and military personnel from all over the world played a crucial role in helping devise a strategy to transport the boys the four grueling kilometers out of a flooded cave.
Thirteen foreign divers joined five Thai Navy divers for the initial rescue Sunday. The team of international experts included the two British divers who originally found the boys on July 2, Richard "Rick" Stanton and John Volanthen.
"Many people are coming," the divers told the boys, as they perched on a rocky ledge deep within the cave, nine days into what would be for some an 18-day ordeal.
The team also included Australian cave-diving medic Dr. Richard Harris, who reportedly canceled his holiday plans after British divers requested his presence at the scene.
Before the first mission Sunday, the Thai Navy SEALs posted a heartwarming picture of three hands clasped together in a show of unity on its Facebook page.
The message alongside it read, "We, the THAI Navy SEALS along with the international diver team, are ready to bring the soccer team home!"
In total, 110 Thai Navy SEALs were deployed to the scene, including off-duty and former members of the elite squad. They lost one of their own on Friday when former Thai Navy Sgt. Saman Kunan died after running out of oxygen in the cave.
His death underscored the risks involved, as teams of two split off to escort each boy out, one sticking close to each child, to ensure he followed the guide ropes. The other swimming behind as a safety measure to ensure everything went as planned.
Danish cave diver Ivan Karadzic, who was stationed at "Camp 6" to assist the rescue divers, told CNN that the divers believed Monday's operation was "even more smoothly executed," than Sunday's.
Alongside volunteers, countries sent their own contingents to to Thailand. Seventeen Australian police divers, 36 US military Pacific Command personnel, and six rescue specialists from Beijing joined the rescue efforts.
Australian Federal Police Commissioner Andrew Colvin said, "This is police cooperation at its very best and highlights the strong partnership with our neighbors."
Jessica Tait, the Public Affairs Officer of the US Air Force echoed the same sentiment, calling the rescue effort "a celebration of humanity."
"This is a Thai-led, multi-national rescue operation, and what's fantastic is that you see the US here, the Australians, the Chinese, the British divers, obviously," she said. "It shows that when militaries train together, it's for this -- it's for the real world."
Other volunteers living in Thailand also pitched in to help, including Israeli diver Rafael Aroush. International companies also offered equipment and expertise.
US billionaire entrepreneur Elon Musk flew in to Thailand Monday with "kid-size" submarines which he suggested could help to bring the boys out.
Musk said based on "feedback from Thailand," the engineers decided to build a tiny sub using a large silver tube meant to be affixed to a SpaceX Falcon 9 rocket.
Musk explained the metal tube would be "[l]ight enough to be carried by 2 divers, small enough to get through narrow gaps" in the cave, and "extremely robust." The device is also outfitted with oxygen ports and a nose cone to protect it from impact with rocks, according to Musk's tweets.
In the end, it was the expert divers who carried the boys to safety.