We came upon a live horseshoe crab (Limulus polyphemus) stranded on the beach last week on Assateague Island. It had gotten stuck in the sand sideways and could not right itself up. The crab was lucky that birds or kids had not yet noticed its legs flailing in the air hopelessly.
After I turned it over, it started crawling awkwardly with its multiple appendages leaving behind shallow scratch marks in the sand.
At the rate it was travelling it would have taken the crab quite some time to reach the safety of the water. So I decided to interfere. After posing with it for a few shots, I released it in the surf. It didn't resurface.