“tide” in Japanese is 潮, read chou, shio (ちょう, しお). It is a Grade 6 Kyōiku kanji, taught in year 6 of Japanese elementary school, and appears in words such as 満潮 (high tide).
What does 潮 mean?
夕方に潮が引いた。
Same sound, different character — the classic trap. Compare them side by side: