Pemuteran snorkeling - where is the good stuff?

I arrived in Pemuteran to do some serious snorkeling in search of octopus and other cephalopods.

I went out to ask around.
A local dive shop told me bio rock is the only good snorkeling in Pemuteran.
Then, a dive shop right near bio rock told me the area between shore and bio rock is good for snorkeling.

But after a night-snorkeling session there, I was extremely disappointed with what I saw at snorkeling depths.
Barely any fish. Coral seemed dead. Sea urchins aplenty.

Can anyone recommend any really good snorkeling spots acceessible from the beach in Pemuteran?
This can't be what I traveled 4 hours by car to get to...

Cheers!