525 dive sites in 61 countries have records of seahorses.
93 confirmed by two or more independent sources, 432 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 70 seahorse sites in PhilippinesDive sites in Philippines
Seahorse sites in Dominican RepublicDive sites in Dominican Republic
Seahorse sites in United KingdomDive sites in United Kingdom
Seahorse sites in Cayman IslandsDive sites in Cayman Islands
Seahorse sites in United Arab EmiratesDive sites in United Arab Emirates