Perhentian islands - snorkelling recommendations?

[Nicool]

Hi everyone,
My sister and her partner are going to visit the Perhentian islands for a few days and asked me for recommendations on where to snorkel (they aren't scuba certified).
I haven't been there and the previous threads I've found were dated/more around Scuba sites.

So, could anyone recommend some good snorkelling spots and operator to go with (they need to rent the gear)?
A good eatery recommendation would be great too

thanks a million
Nicolas