A hermit crab who has outgrown his old shell moves into a new one, which he decorates and enhances with the various sea creatures he meets in his travels.

"Hermit Crab has outgrown his shell; it's time for an upgrade. The beach is strewn with options, but none are quite right. A rock is too heavy; a tin can is too noisy; a fishing net too many holes. When a giant wave sends Hermit Crab careening toward a hungry porcupine fish, there can be no more dillydallying. He needs a new home to hide in -- and fast!"--

Ten little hermit crabs who go to the beach disappear one by one.

Absorbed in his search for food, a shy hermit crab, disguised in a fancy new shell, inadvertently rescues a flounder caught beneath a trap and wins the admiration of the other marine animals.

When Sebastian the crab has a bad day, nothing that Ariel and his other friends do seems to cheer him up, until he realizes how lucky he is to have such good friends.

A seagull is enjoying a perfect day until a disagreeable crab comes along, but by sunset, they have discovered what really makes a day perfect.

Crabby is a very grumpy crab, so Plankton tries to find a game that will cheer Crabby up, but Crabby does not want to play Simon says or hide-and-seek---will a game of tag be more to Crabby's taste?

Six stories about the activities and experiences of a first grade class.