Underwater

This information is to bring your expectations regarding Koh Samui closer to the reality. There is a lot written about Koh Samui, but sometimes this is not what you will find on the island. The water is described as blue and crystal clear, which is not really wrong, but you will find it only on a few days depending on the wind.

In the ocean around Koh Samui there are only a few spots more than six meters deep, and in the last few years a lot of roads were built. Rain washed red sand into the sea and this red dirt is much more lighter than the coral sand. With current and waves the sediments can come up and the visibility will go down, to sometimes less than one meter.

Koh Tao is in the north of Koh Samui and the depth around Koh Tao is 40 meters and more. The depth of the dive sites is 10 to 25 meters and the visibility is usually between 10 and 20 meters all year round. On some days the plankton can reduce the visibility down to 5 meters, but this is a rarity.

Sailrock, Southwest and Chumphon Pinnacle are in deep water up to 40 meters and the visibility can extend to 30 meters and more. All three dive sites may have a thermo cline in 20 meters, where the visibility is only 2 or 3 meters. Usually you can expect less fish with very good visibility.

The Angthong Marine National Park is located to the west of Koh Samui. It is an island park with depths from 5 to 20 meters. There usually are dive excursions to the northern islands (Koh Wau & Koh Tungku) where the depth between the islands is up to 20 meters. You will find visibility beyond 5 meters approximately fifty days per year.