I have visited this island on several occasions with Coral Princess Cruises and Noble Caledonia.
Rajah Ampat is a remote area well known for it's high coral and fish diversity, possibly the world's highest. Misool Island hosts some of the most spectacular views and coral reefs of Rajah Ampat.
The best geology and coral reef snorkelling is in the area off the islands south east, where it breaks up into jagged peaks. Unlike other ares of Rajah Ampat, there are some small beaches, these tend to be made up of jagged coral bits.
The botany is varied, and there are often many plants flowering, including orchids and the Misool Pitcher plant...
Some of the snorkelling is great. Coral reefs can be found in small secluded bays, and often drop off right under the limestone and overhanging rainforest. If you are an experienced underwater naturalist, you may not find the clearest waters and brightest reefs, but you will probably notice many smaller species of fish that have not seen before.
Birds include Eastern Reef Egret, Striated Heron, Brahminy Kite, Blyths Hornbill..
At the time of writing (2019), expeditions ships were not allows in the Rajah Ampat area.