Grey seals are intelligent and inquisitive predators; as pups, they have a lot to learn about how to survive in their environment, in a short time - especially things like judging the force of waves against rocks, where to find food and how to catch it. Solitary water-play is one way of learning - watch how this pup rotates and swims upside down (having nostrils that can close is a real advantage over us humans), splashes and blows bubbles, then rushes to catch up with Mum who seems to be foraging under an overhanging cliff. It is hard to see what exactly is happening when she surfaces and they nuzzle each other nose to nose, but as the female swims away, the pup demonstrates quite a turn of speed with a few swishes of the hind flippers to keep up. All my books on British mammals say that grey seal mothers leave their pups on remote beaches, and that the pups shed their white baby fur, or lanugo, before taking to the sea. Here we see affiliative behaviour between a white-coated pup and what appears to be the mother, in water. When the pup hauled out on the beach for a rest, the mother waited in the water nearby, and shortly afterwards I filmed this, which now becomes the 54th #BrightenYourDay video to lift spirits (especially among those of us living inland and missing the sea) during #Covid19 #lockdown.
I would welcome any seal biologist viewing this to comment on the behaviour in this video (we watched the presumed mother and pup for two periods of about 15 minutes each on a day in late September). Are we seeing a Welsh equivalent to the dilemma - suckle or swim - reported in Scottish grey seal colonies? See: http://news.bbc.co.uk/earth/hi/earth_news/newsid_9134000/9134947.stm

The Pembrokeshire Coast Path provides many opportunities to look down into coves such as this one, beneath Strumble Head Lighthouse - which is on St Michael's Island, accessed from mainland Wales by a spectacular suspension bridge (closed to the public) over the narrow sheer-sided channel https://www.trinityhouse.co.uk/lighthouses-and-lightvessels/strumble-head-lighthouse. The lighthouse has been fully automated since 1980 so the wildlife is pretty much left to its own devices most of the time, and seals can haul up onto the pebbly beach to rest.

Grey seals Halichoerus grypus are protected in UK and their numbers have recovered from 19th/early 20th century hunting to the point that some have called for a resumption of culling to 'protect fish stocks'. Research into seal diet, however, showed that they eat lots of sand eels (which humans don't) and not very many salmon (which humans do) - for more info check the Mammal Society website https://www.mammal.org.uk/species-hub/full-species-hub/discover-mammals/species-grey-seal/