Just got back from the Similans (Feb. 20-23). Mantas, zebra sharks and an eagle ray at Bon (and a black blotched stingray at Bon Pinnacle) but missed the whale shark(s) at Richelieu - plenty of barracuda, various cephalopod and nudi actions though, plus a very nice frogfish. The amount and density of schooling fish was stunning. Vis was generally very good in the Similans (and during the two dives we did at South Surin). Temp range: 24-27 degrees C.