Bouying Porp's

No wind , no rain for a couple of hours this morning so I had a look off the outer breakwater of Fishguard Harbour. It took a while to spot anything but after a while I noticed a mother and calf "bouying" The much smaller calf was bouying and quite distant, near to a couple of lobster pot bouys. It took a while before I managed to ascertain the small dark shape was actually a baby Porpoise and it was only when a large adult surfaced alongside that I realised it was a mother and calf.
I am not sure "bouying" is a phenomena that has been described before but It seems to happen not infrequently.
When a mother porpoise has a youngster that is still pretty dependant but she needs to feed, quite often she will leave the youngster swimming around near a pot bouy. This then allows her to go off and feed. every so often she comes back to check her pup which seems to just bobble about around the bouy for the few minutes between parental visits This can go on for quite a while but if some threat of danger occurs like a boat approaching from a distance of say several hundred metres, the mother will come and take the calf away.
I have seen this happen quite a lot over the years and on a couple of occasions several calves left together in a kind of crèche situation. at these times the youngsters eseem to indulge in some quite playful behaviour with tail slapping and splashy behaviour!