The head of the Joint Command Centre, Narongsak Osottanakorn, has just released details about the progress of the rescue operation.
He said the operation began at 10 local time (03:00 GMT), when 13 international divers entered the cave.
He said 10 of them headed for Chamber 9 (where the boys are) and Chamber 6 (near the junction) as planned. Another three cave divers joined the operation at 14:00 local time.
There are a number of additional rescue personnel - including divers from Thailand, the US, Australia, China and Europe - stationed from Chamber 3 to the entrance.
This includes a rope system to assist over difficult terrain in Chambers 2 and 3.