234 dive sites in 50 countries have records of mackerel.
32 confirmed by two or more independent sources, 202 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.
All 18 mackerel sites in PhilippinesDive sites in Philippines
Mackerel sites in United KingdomDive sites in United Kingdom
Mackerel sites in U.S. Virgin IslandsDive sites in U.S. Virgin Islands