Abby the Saint Bernard / Chesapeake Bay Retriever mix (Saint Chesa Bay Bernard) as a puppy at 10 months old—"Her mother is a short hair Saint Bernard and her father is a Chesapeake Bay Retriever."
The Saint Chesa Bay Bernard is not a purebred dog. It is a cross between the Chesapeake Bay Retriever and the Saint Bernard. The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.