This video from British Columbia in Canada says about itself:
Helpless Porpoise Rescued
30 April 2011
On April 26, 2011, a rare live stranding of an adult Harbour Porpoise occurred on Salt Spring Island. Island Wildlife Natural Care Centre, a local non profit marine mammal rescue centre responded to the stranding. Staff members guided the struggling animal ashore, administered some basic, supportive care, and transported the porpoise to the Island Wildlife facility where the porpoise was kept afloat in one of its marine mammal tanks.
The porpoise was later transported to the Ganges Coast Guard Station and loaded aboard the Coast Guard hover craft, Siyay, which rushed the animal to the Vancouver Aquarium who have more Cetacean rehabilitation expertise.
From the Lincolnshire Echo in England, with video there:
Porpoise rescued from muddy river bank at Gibraltar Point
February 20, 2015
Volunteers from Natureland Seal Sanctuary in Skegness came to its rescue after it became stranded when the tide had gone out.
The rescuers had to be roped up for their own safety due to the muddy conditions on the riverbank.
They managed to get the porpoise onto a stretcher before transferring it to the beach.
They then waded through the sea water until it was deep enough to release the porpoise.