This is the 158th most frequent Spanish word.
claro
Clear; obvious; light (in color).
Here, 'claro' is used as an interjection meaning 'of course' or 'sure', emphasizing agreement or acknowledgment.
Claro, entiendo lo que dices.
Of course, I understand what you are saying.
In this case, 'clara' (feminine form of 'claro') is an adjective describing the transparency of the water.
El agua de esta playa es muy clara.
The water at this beach is very clear.
Here, 'claro' is used as an adjective to mean 'clear', metaphorically representing clarity or absence of confusion in understanding the matter.