Ssssh! Don't wake up the sleeping California sea lion. Sea lions "raft" together with one of their pectoral flippers in the air. This behavior alters their silhouette and perhaps makes them less of a target for predatory sharks. Evidence also suggests this behavior warms or cools the body depending on the weather and sea temp
Zalophus californianus rafting COSE 2014 11-05 SB Channel-008
A rafting California Sea Lion (Zalophus californianus). The most widely quoted hypothesis about this behavior has to do with the animal thermoregulating...maintaining its core body temperature despite fluctuating ocean and air temperatures.
From 2010 04-02 SB Coast