Gorgonians are the sea fans. They are a type of octocoral with Gorgonin giving them structural strength. They are filter feeders and are often in areas with strong currents. There were many like this at Kashiragashima under a bridge with strong currents. Goto 2015
This might be Echinomuricea peterseni アザミヤギ. This bright Octocoral with large polyps. Enoshima 2011
A red Sea Fan. Amami 2024
A yellow Sea Fan. Amami 2024
A red Sea Fan growing down from the top of a swim through. Amami 2023
A small Gorgonian growing on a wall. Enoshima 2018
Another Gorgonian growing on a wall. Enoshima 2018
This seems to be Echinomuricea peterseni アザミヤギ. Close up of the Coral Polyps. Enoshima 2018