Yet another beautiful dawn, but with extra bits

Thailand 2017, Day 21
This was the view from our balcony at 6:25 this morning. That's the best time of the day, as the light is beautiful, the sun is not too hot, and there is hardly anyone else about.
Along with a young British couple that we met on the way to this island, we hired a long-tailed boat today, to take us out to some of the limestone karsts (the largest being Ko Cheuk) to go snorkelling. The boat we hired takes up to 8 people, so it was great for just the 4 of us. The highlight of our day, and the reason we wanted to go, was Tham Morakot (Emerald Cave) which is a stunning limestone tunnel, over 80 metres long, and quite low - far too low for a boat. It leads from what looks like just a small opening in the cliff face, and cannot be accessed at high tide. Evidently at some states of the tide it is shallow enough to walk through - but certainly the water was quite deep when we visited. There was quite a swell in the first part of the tunnel, so we had to be careful not to be knocked against the walls or the roof by the waves - both were covered in shell-like deposits and looked extremely sharp!
 We swam through the tunnel with our guide who was wearing a head torch, as it is really dark for quite a long way. Eventually we could see daylight, and we emerged into a horng (semi-submerged island cave). It was really amazing and quite beautiful, like a lush tropical garden  with a beautiful sandy beach. It was almost like a natural cathedral, with vertical limestone cliffs all around us, and with a piercing shaft of light illuminating the beach. 
Evidently pirates used to use it to stash away their treasure. It was then forgotten about until relatively recently when it was spotted by the use of aerial photography. 
There were just the 4 of us when we visited, plus our guide, and it was quite magical.
As we emerged once more into daylight and the open sea, a large day boat had arrived with about 60 Chinese visitors. They were all in a long snake, each person holding onto the one in front, and roped together, and all wearing fluorescent lifejackets.  Evidently some of these groups chant "We can do this, we will do this" (in Chinese) as they swim through the tunnel, to give themselves encouragement to get through (it's quite hard work, especially if you can't swim as many of them can't). I'm so glad that we managed our visit when no-one else was there - it would have rather spoiled a special moment to have 60 people in a long snake, all chanting! 
C (Nikonabike) has blipped the large group on their way from the boat, as he had his waterproof camera with him (do have a look if you get a chance - it's a great shot). I must say, they all looked very happy, although there were squeals of terror coming from their group. I had no photographs as obviously you couldn't take a "normal" camera in there - it was hard enough swimming through as it was!
My extra is of the daily volleyball game played by the local lads.