shallow streams are noisy; deep rivers flow silently; empty vessels make the most sound
Proverb meaning that those with little knowledge or depth tend to talk the most, while the truly wise are quiet. Literally: 'In shallows, noisy waves.'
As the proverb 'shallow streams are noisy' says, truly wise people don't talk much.
A similar proverb meaning 'a skilled hawk hides its talons'; emphasizes hiding one's abilities rather than the contrast between shallow and deep.
A more direct equivalent: 'empty barrels make the most noise'; closer in imagery to the English 'empty vessels make the most sound'.
A traditional Japanese proverb. The imagery contrasts shallow water, where waves are easily stirred up, with deep water that remains calm, metaphorically applied to human knowledge and speech.