Mae Haad, Koh Tao · Daily, 8am or 2pm
Certifications don't expire, but confidence does. If it's been a couple of years, half a morning in the pool running through the skills is the difference between a first dive back you enjoy and one you spend fighting your own buoyancy.
There's also a practical reason: dive insurance generally requires divers with under 60 logged dives to show a dive within the last six months. A refresher satisfies that, so you can join fun dives the same afternoon.
Ascent rates, no-decompression limits, how to read your computer, and the safety checks that quietly stopped being automatic.
This is a skills review, not a course. What it does is make you current for insurance purposes and get your hands working again, so you can join fun dives straight afterwards.
Certified years ago, haven't dived since. This is exactly what it's for.
Under 60 dives and none in six months? This makes you current.
Dived in the last few months? You almost certainly don't need this.
You need Open Water or Scuba Diver first — there's nothing here to refresh yet.