The 12 boys trapped in a Thai cave say "Don't worry, everyone is strong" in the first letter sent out through drivers, while their coach has apologised to their parents.
"When we get out of here, we want to eat many things. We want to go home as soon as possible," adds the message, which was handwritten in blue ink on notebook paper and carried out by a foreign rescue diver late on Friday.
A total of seven pages were posted on the Thai Navy SEALs Facebook page, with messages apparently from each of the boys - aged 11 to 16 - and their 25-year-old coach. Their brief notes express gratitude, love as well as dreams of food.
"I want to eat pan-fried pork," one of the boys writes.
The 25-year-old coach says: "To the parents of all the kids, right now the kids are all fine, the crew are taking good care. I promise I will care for the kids as best as possible. I want to say thanks for all the support and I want to apologise to the parents."
The group has been trapped more than 4km inside the cave in northern Thailand since June 23.
A flash flood blocked their way out and parts of the cave remain submerged in water, even as rescuers frantically work to drain it with industrial pumps.
Rescuers say they will not immediately attempt an underwater evacuation because the boys have not yet learned adequate diving skills.
However, if heavy rains start again, divers will try to take the boys out right away.