Unidentified object

[finnaest1]

Does anybody know what this is? Saw it at my local beach and have no clue. Thought this would be the place to go. For context this is in San Diego, and the organism inside was pulsing and seemed like it was trying to get out of the sac it was in.

 

[Nihil]

These are Buoy Barnacles

 

[finnaest1]

These are Buoy Barnacles

Great call. Thank you!