Porites is a Genera of coral. It is very common. It is even more important in Hawaii where many types of coral are absent. It makes giant coral heads, forms plate corals finger corals, knobby coral and encrusting corals. Above is a close up of Porites polyps. Kauai 2013
Porites polyps. Kauai 2017
A finger or knobby form of Porites. Kauai 2018