CC BY-SA 4.0, Wikimedia CommonsSeasonal· Richelieu Rock· Thailand
Whale Shark Season (Feb–Apr, Richelieu)
9° 21.8′ N · 98° 1.3′ E
The late dry season, when plankton rises along the Andaman pinnacles and whale sharks are most likely at Richelieu Rock, Koh Tachai, Koh Bon and Elephant Head Rock.
Practical
Coordinate is the OSM-mapped Richelieu Rock dive site. Wikipedia and Sea Bees give February to April as the best time for whale sharks and mantas at Richelieu; the Southeast Asia Pilot says they are often seen in March and April. Khao Lak Explorer says the season starts around January and runs to the end of May, varying by year. Sightings are never guaranteed (Wikipedia calls them rare), so more dives mean more chances. Keep at least a few metres away and never touch them.
Best for
Timing a whale shark trip
Season
Best February to April