内湾

1. Origins, structure, and basic meaning

• Structure: 内湾 (ないわん) is an inner bay enclosed by land relative to open sea. It appears as a harbor location and a survey area.
• Basic usage: A small harbor lies in sheltered waters; a research vessel records water quality there over time.

2. Common pitfalls and similar expressions

• Sheltered harbor location and body of water under study
  • 内湾に locates the harbor, while 内湾の水質 makes the bay's water a research subject. The example does not prove that every inner bay is always calm.