tuì cháo / hòu / qiǎn jiāo / lù chū / shuǐ miàn / chuán zhī / bì xū / yán zhe / biāo jì / háng dào / xíng shǐ

退潮后，浅礁露出水面，船只必须沿着标记航道行驶。

After the tide went out, the shallow reef emerged above the water, so boats had to follow the marked channel.