渦潮

1. Origins, structure, and basic meaning

• Structure: 渦潮, read うずしお, means a swirling tidal current or tidal whirlpool.
• Basic usage: It describes whirlpools seen in a strait or swirling currents that a boat navigates around.
  • 展望台から海峡の大きな渦潮が見えた。

2. Common pitfalls and similar expressions

• 渦 and tidal flow
  • 渦 broadly refers to a whirl or vortex, while 渦潮 refers to one formed by tidal currents. Not every swirling liquid is a 渦潮.