The divers from the Thai navy's elite SEAL unit were paving their way through murky waters filling passages of the 10 km underground maze of the Tham Luang cave, reports Xinhua news agency.
They are trying to set up a control centre in a chamber, about 3 kilometers away from where the boys are believed to be.
The water pumped out from the cave is less muddy than it was three days ago, meaning that there was less water coming from outside, said the governor.
Divers reached the same spot earlier in the week but were forced back by rushing floodwaters.
The weather was clear in the last two days, allowing the rescue team to pick up the pace to pump the floodwater from the cave.
The divers brought 200 bottles of oxygen to the cave and left them every 25 metres along the tunnel walls so swimmers navigating the muddy pools with almost no visibility could stay under for longer.
Australian and Chinese specialists also headed for Thailand on Saturday to join the search.
The 12 Thai boys, aged between 11 and 16, with their 25-year-old coach went missing on June 23 in the cave in Chiang Rai province.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
