Is it safe to swim in Nha Trang right now, or are there jellyfish and stinging plankton in the sea?

On August 16, one chat participant replied that jellyfish are common in many places and not something unique to Vietnam, and that sea lice/plankton aren't that big of a problem in his view — suggesting it's not worth over-worrying.

A fresh report from August 10 says stinging plankton was again present in the central sea area, and many swimmers weren't aware beforehand. It feels like a needle prick, and some people develop an allergic reaction afterward with skin spots/rash.

A separate warning specifically about night swimming: in darkness it's almost impossible to spot dangerous jellyfish (like box jellyfish or Portuguese man o'war), whose stings can cause severe shock or even paralysis. At night, sea urchins and stingrays also move closer to shore into shallow water, making it easy to step on their venomous spines.

A fresh report from July 22 notes sea urchins were spotted on the seabed, and plankton occasionally stings but mildly — just a slight pinch, not painful.

The newest chat message specifically asked about beach conditions in the last few days and whether plankton or jellyfish were currently present. That suggests swimmers in Nha Trang treat this as a real-time issue that can change from one day to the next.

At the beginning of July, travelers were already asking whether people had stopped swimming because of stinging plankton that feels like nettles. So the practical concern being discussed was not a formal swimming ban, but the chance of getting a painful skin sting in the water.

The only actual reply was sarcastic, joking about rumors that everything was terrible and that plankton and jellyfish were attacking everyone. The cautious takeaway is that the chat did not confirm a major widespread outbreak, but it also did not provide a precise update for any specific beach.