Like ducks to water

I hear giddy voices.
Five would-be swimmers
Slap-slapping down the long, stone steps
And just where the orchard turns, their footfall
Deadened. Through summer-long grass,
they zig-zag, snatching at seedheads -- then plop
Into the slow, shallow stream.
Beaks green with weed.
Five silent swimmers.

Inspired by De’s quadrille prompt in 44 words: Stream