Clam Digs into Sand to Hide itself
Many people have share many videos of clams moving in water to search for food or to escape from preys, but this video of a razor clam shows movements that are never been captured on camera before and you can also hear some weird noises made by the clam.
There is also a debate going online in which many people claim that it's a Geoduck which is also a kind of saltwater clam.
As such I am not expert on this topic. You can look at it yourself and make a decision on this.