One from the KM 18 trail - had a hide session by the stream but drew a blank until this Malayan softshell turtle (Dogania subplana) [kindly ID'ed by Herp Guide Parinya on Facebook] decided to pop out of the water for a short while. They must have good eye sight because he/she locked onto to me straight away and was off.
Many turtle species have good eyesight. Sometimes when hiking along rivers they drop themselves into the water even if I am 50+m away and not even clearly visible.
I have seen this species a couple of times right at the river crossings in kk, in some cases if I had not seen it I might had run over it. Sometimes when this species senses danger it digs itself into the sand under water and becomes virtually invisible.