The Australian authors—Dr Neil Banham (lead) and Dr John Lippmann—reported that a 26-year-old healthy male freediver dived to 10m (32.8ft) where he met a friend who was diving on scuba. The freediver breathed from a scuba regulator before ascending.

It may have been that he held much of his breath during ascent, which would have been his usual and generally safe practice with normal breath hold diving. — Banham, Lippmann

What we see is that sharks are being targeted by international factory fleets around the world who trail millions upon millions of baited hooks through their realm, trawl the sea floors for rays, skates and other bottom dwellers to 4,000 metres, and slaughter them by the millions. Sharks are the only profitable prey remaining, now that ninety percent of the original (fish) fisheries are fished out.

The Wildlife Trusts, which comprises 46 individual wildlife trusts around the country, reports record numbers of more than 800 sightings of whales, dolphins and seals in the waters of the United Kingdom in 2019.

Its Yorkshire project reported hundreds of individual sightings by trained citizen scientists. Among these were a pod of bottlenose dolphins making their way from Scotland to Flamborough Head in East Yorkshire-the farthest south they had been officially identified.

Lunge-feeding humpback whales plunge into dense schools of small fish to feed on them. However, these small fish tend to be pretty fast. So, just how do huge whales sneak up on such speedy prey if they are as huge and overbearing as a ... well, whale?

This question became the focus of a study at Stanford University. Its findings was subsequently published in the Proceedings of the National Academy of Sciences journal.