For the Ragtag Daily Prompt: spiky.
So this is a beach. Why spiky? The tide is way out. Watch where you step or sit, because these are the spiky bits!
Barnacles! The live ones are closed with the water out, but the dead shells are also sharp and spiky. Bits that aren’t spiky are slick!
I took these on North Beach last May. Wear shoes or at least carry them.