In Phuket, the head of the lifeguard service spoke to local media outlet The Phuket News about safety rules and noted that people should only enter the water when lifeguards are present on the beach:
"Lifeguards are there to keep an eye on beachgoers and check where there are safe areas for swimming. I want tourists to know this. I want tourists to be safe. Please do not swim at beaches without lifeguards; they are unsafe."

The man also noted that sometimes Russian tourists are overly bold and disregard safety precautions, sailing far from shore or ignoring warning signs: "Two Russian tourists couldn't return to shore due to the current and huge waves; they were being swept further out to sea, and I had to use a surfboard to help them. Then I had to run to help another Russian tourist who ignored the red flags and also found himself in mortal danger. It was very difficult to pull these tourists to shore, as the wind and waves were very strong."
Underwater currents are one of the main dangers for beachgoers. They are caused by the tides and are only a few meters wide. If caught in one, the safest course is to swim calmly along the shoreline, avoiding the effort of fighting the ocean. Currents rarely run parallel to the shore, making it possible to escape the current much more quickly.
Jellyfish also pose a danger. Their stings are painful, but not fatal. If stung, it's recommended to immediately swim away from the jellyfish and get to shore, where you can neutralize the pain with vinegar.
Source: trn-news.ru