Can you help me to explain this sentence:
Mr. Bob said: “Come on people; we haven’t got all day. It’ll be time to get out again before you set foot in the water.”
(Mr.Bob was a swimming instructor in a college; he was speaking to pupils at the swimming pool; but I don’t understand what he means when he said : It’ll be time to get out again before you set foot in the water.)
Thank you!
Jung