Charles Zhang's reminded swimmers of risks

Charles Zhang's bay crossing in Shantou was not a smooth campaign. He reminded everyone not to attempt swimming in this sea area lightly. The currents and the oyster zones are not a big issue on their own, but the combination of the two is extremely dangerous: “The current flows at about 3 km/h. If your swimming speed does not exceed 3 km/h, I recommend not swimming in these waters.”