A rescued false killer whale calf has been moved to a larger pool at the Vancouver Aquarium, six weeks after it was found stranded and near death on a Vancouver Island beach.

The young whale, nicknamed "Chester," is slowly recovering his weight and strength after the stranding ordeal that left him unable to swim and dangerously underweight.

Now he's on the mend and ready to test his strength in a pool that will let him dive deeper and swim faster.

But Chester's health is still feeble, and aquarium veterinarians continue to watch him 24 hours a day.

The whale has been at the Vancouver Aquarium since mid-July, when caregivers said the odds were "stacked against" his survival.

Chester washed up on a beach near Tofino on July 10. He was found badly injured, with many scrapes and cuts across his skin.

False killer whales are a rarely-seen, rarely-studied relative of the dolphin.