• 潟かた — lagoon / inlet
• 干潟ひがた — tidal flat
• 潟湖せきこ — lagoon (formal)
• 砂潟さかた — sandbar lagoon
• 新潟にいがた — Niigata (place name)

潟 uses the water radical 氵 to indicate something related to seas or rivers. The rest of the kanji provides the sound and meaning of a geographical feature shaped by water and tides. You’ll often see this kanji in place names, such as 新潟 (Niigata), where shallow or receding water creates unique landforms.