Blowhole

Three treasurer seekers were in the water looking for lost treasures with snorkels, masks and fins.
One pink balloon escaped up into the sky.  Who takes a balloon to the beach . .?
I think I know why the signpost sings - I noticed half-inch holes unevenly spaced on the current windward side and the winds are moderate (have been for a few days).   It's an eerie sound, reminiscent of whale song, quite haunting heard at the beach. 

Pink was the colour of the day, I notice.    Happy Monday!

(I slept the afternoon away.)