23 dive sites in 5 countries have records of blue-ringed octopuses.
23 reported by one source.
Sites are ranked by evidence: first by how many independent divers logged the animal there, then by how many independent sources confirm it. "Best" here means most independently confirmed, nothing more.
Blue-ringed octopus sites in PhilippinesDive sites in Philippines
Blue-ringed octopus sites in AustraliaDive sites in Australia
Blue-ringed octopus sites in IndonesiaDive sites in Indonesia