CHIANG RAI, THAILAND — Twelve boys and their soccer coach were finally found nine days after going missing inside a northern Thailand cave, but the problem now is how to get them out.

With most of the passageways inside Chiang Rai's complex Tham Luang cave system still underwater, there are four options to safely extract the trapped boys, reports the BBC.

Rescuers are pumping water out of the cave to create walkable conditions, and have drained the first 1.5 kilometers. But the operation could be set back by heavy rains predicted in the coming days.

Rising waters may force the team to dive to safety, donning full scuba masks and suits and being guided by experienced divers through the 5-hour journey with the help of guide ropes, according to the Guardian.

But though this method is the fastest, it's also the most dangerous. The dive through narrow passageways under zero-visibility conditions is risky even for seasoned divers.

One rescue diver has already died after delivering supplies to the trapped team.

A third option being considered is drilling into the cave from above and pulling the boys out, but this is the least feasible since it requires a thorough survey of the cave system to know where to drill.

If all else fails, officials say the boys and their coach have enough food and water to last them through the four-month wait for flood waters to recede, so they can walk out.

For now, rescuers are keeping an eye on the team and monitoring their condition. A fiber optic cable is also being fitted so the boys can talk to their worried parents.