Koh Maithon is a small island off Phuket's south-east coast, similar in character to nearby Koh Lon — a quiet, low-key escape reachable on a short boat trip.
What it's like
A single main beach with genuinely clear water, minimal development, and a much smaller visitor footprint than the west coast's main islands like Phi Phi or Racha.
Snorkelling
The clear water and limited development make this a reasonable snorkelling stop in its own right, generally with fewer other boats and swimmers sharing the water than the more established island tours.
Why visit
Proximity combined with quiet — a realistic half-day or full-day trip without the crowds of the better-known island tours. Often bundled with a stop at Koh Lon on the same route given how close the two islands sit to each other.
Getting there
Longtail boats run from Chalong or Rawai piers — check current schedules directly with a boat operator rather than assuming frequent departures, since services here are less frequent than the main tourist routes.