Ko Hong Trip Report - visited February 2014 (and August 2013).
There are 2 Ko Hongs in Phang Nga Bay. This page concentrates on the southern one between the western Krabi coast and Ko Yao Noi. The northern/north-western one is best visited on the trips out of Phang Nga town and Phuket. A hong is a former cave whose roof has collapsed, oftren joined to the sea by a tunnel. The southern one is huge, the northern one pretty compact, only accessed by kayak from memory. The southern one has a very nice beach nearby, which you can't say for the north/north-western bay islands.
The August 2013 visit out of Railay.
This was a 3 island trip with most time spent on Ko Hong. Price was 1400 each including lunch. I don't know if it included National Park entry - certainly no one asked us to pay extra. But maybe that is a low season thing.
Boleslav has some info and pix on a kayaking trip to Ko Lading on the Ko Yao Noi Trip Report page.
There are pix and info on the more western and northern Phang Nga Bay islands including the smaller Ko Hong on this page.
IF YOU SEE MISTAKES OR HAVE EXTRA INFO PLEASE POST BELOW. BUT IF YOU HAVE QUESTIONS PLEASE ASK THEM ON THE FORUM PAGE WHICH CAN BE ACCESSED VIA THE MAIN BEACHES AND ISLAND INDEX. I SELDOM CHECK THESE INDIVIDUAL ISLAND REPORTS WHEREAS I VISIT THE FORUM MOST DAYS WHEN NOT TRAVELLING.