MAE SAI, Thailand - Relief has given way to anxiety around the site of a vast cave complex where a soccer team of 12 boys and their 25-year-old coach remain trapped after 11 days, as rescuers deliberate the best way to extract them before severe storms hit.

The boys were being given rudimentary diving lessons Wednesday, even though none of them knows how to swim. Though water levels have receded, volunteer divers who have spent hours deep in the cave complex say currents remain strong, and even they have to hold on to ropes to haul themselves out.

"The water is still too rough for the boys now," said Tiraya Jaikaew, who leads a team of volunteer rescue divers helping the Thai navy. "We are focusing on setting up ropes in each section of the cave to help them."

The 11-day drama has riveted the country and much of the outside world after the young soccer players, ranging in age from 11 to 16, disappeared while exploring the vast Tham Luang cave complex and then were trapped by rising floodwaters.

Divers finally found them huddled on a patch of dry ledge in one chamber, but getting them out remains a problem. The 2.5-mile journey through winding, flooded passages would normally be navigable by only the most experienced divers.

Thai authorities are also hoping to remove enough water, so perhaps the boys could escape by foot, with their heads right above the water level. After pumping out about 30 million gallons, they've reduced water levels by 30 to 40 percent, they said Wednesday. Unseasonably dry weather has helped, but it is not predicted to last.

If the boys can be trained up and the water sufficiently reduced, an extraction could happen within days, they added.

At the rescue site Wednesday afternoon, Thai soldiers conducted their first evacuation drill - locking arms as they formed a column from the cave's entrance to a field, where 13 ambulances were waiting to bring the group to the hospital.

The drill simulated what a rescue would look like and how the boys would be transported to a hospital when they are eventually freed from the cave. It also raised hope among family members, some of whom have stayed at the chaotic, muddy site where rescue operations are being coordinated since the boys went missing. An aunt of one of the boys, who declined to be named because of strict controls around their interactions with press, said authorities had told her a rescue could be staged as soon as Thursday.

More rains are predicted for the weekend, and Thailand's monsoon season will stretch until September. If a rescue attempt is not made soon, it may be months before the boys and their coach see daylight.

Videos released Wednesday by the Thai navy, which is overseeing the effort, show the boys in apparently good spirits, introducing themselves to the camera, with their palms pressed together in the traditional greeting.

Another video shows a Thai doctor, who spent the night with them in the cave, treating their cuts and bruises and joking with the boys, many of whom appear to have new clothes and were wrapped in foil, heat-retaining blankets.

Thai authorities have emphasized that they will not endanger the boys' lives during the extraction and will only do it when it is "100 percent safe."

"The water is very strong and space is narrow. Extracting the children takes a lot of people," Deputy Prime Minister Prawit Wongsuwan told reporters, according to Reuters. "Now we are teaching the children to swim and dive."

After days of solitude, the boys are now receiving a string of visitors, including rescue divers and health professionals, and they are being fed liquid, high-protein food.

Divers are also attempting to string a fiber-optic cable through the caves to give them phone contact with the outside world and their families. But even that has been a fraught process. The cable has not yet gotten within 50 yards of the boys, the range in which it can provide a service akin to a home wireless connection. An official from CAT Telecom, a state-owned company that runs Thailand's telecoms infrastructure, said rescuers would have to dive for another four hours to get the cable close enough.

The boys were first found by a pair of British divers who described a harrowing three-hour round trip through narrow passageways flooded with water while trying to fight a strong current - indicating the magnitude of the challenge to bring them out along the same route.

The world's attention has been riveted to their story, which echoes the tale of the 33 Chilean miners who were trapped for 69 days nearly a half-mile below the surface in 2010. Engineers there eventually drilled a vertical hole to reach their chamber, and all the miners were pulled to the surface one by one.

The complexity of the Thai cave in the northern province of Chiang Rai with its honeycomb of chambers and passageways, however, makes drilling a hole as an escape route an unlikely option.

"They shouldn't be ashamed to be scared," Omar Reygadas, one of the trapped Chilean miners, told The Associated Press. He ascribed his comrades' survival to faith, prayer and humor. "Because we were scared, too. Our tears also ran. Even as adult men, we cried."

Thousands of journalists had descended on the quiet town of Mae Sai by Wednesday, close to Thailand's border with Myanmar. At the rescue site near the cave complex, vehicles ranging from SUVs to motorcycles zigzag in and out along the muddy terrain, as vendors set up noodle stalls and massage booths for the volunteers.

For volunteer divers like Jaikaew, being among the Navy and the rescuers was simply a calling. Jaikaew, who runs a computer repair shop, has temporarily closed his day business in Lampang, about 140 miles south, and moved to the site to help coordinate the Thai navy's rescue efforts.

"I have spent 10 years as a rescuer, but nothing has ever been like this," he said. "I've never seen an effort as big as this in my life. It is really special."

The Washington Post's Shibani Mahtani and Jittrapon Kaicome wrote this article.