Cachalot is an ocean world with almost no land — just low coral reefs. It has been given to the cetaceans in recompense for the depredations commited against their species over the centuries. But now the fragile treaty between them and the humans is under attack by unprovoked attacks upon human settlements by the cetaceans. There is no sign of the cause. The conclusion of the investigation leads all involved to speed up their plans for their future development…. Only the humans are out of the loop. ( )

A mother-daughter biology team is dispatched to a water-world (Cachalot) to try to figure out what has happened to three floating cities that were completely destroyed. The kicker is that several hundred years earlier, humans helped to relocate whales from Earth to Cachalot - giving the planet over the whales. Humans are visitors on Cachalot - tolerated by the whales so long as they don't interfere with the lives of the whales. But the whales are the only ones who might know what happened to the cities.

A kind of "meh" story. A little sex. Nothing much silly or funny. The whole neurophone was so obviously going to be the thing that saved them, it wasn't even marginally surprising that it was used when it was. Even Pucara's duality was unsurprising. Even the romantic entanglements weren't resolved. The more I think about it, the more disappointed I am in the book. ( )

Another old favourite back in the 90s. Part of the Humanx series, set before the main Pip and Flinx books, this is a mystery set on the ocean world Cachalot where most of the remaining cetaceans live following the discovery of a serum that greatly expanded their consciousness. They tolerate a small human colony and permit them to harvest various marine products provided they do not interact with the cetacea unless invited to do so (cetecea have long memories and don’t like humans because of past genocidal activity).

The cetacea have formed societies based on relative intelligence (the toothed whales being the most intelligent, and the baleen the least), and their participation in their philosophical journey - the porpoises preferring to play rather than mess around with all this thinking stuff.

The human colony are largely based in floating cities, dry land being minimal and barely above sea level. The trouble is that several of these cities have vanished; leaving no survivors and no real clue about what has happened. So a group of experts has been sent to find out what has happened.

No real mystery here; it’s fairly obvious who did it (especially if you own the original paperback), the main twist being the reason why. It does have elements that would appeal to modern readers in the interactions between cetacea and humanity even though the book was first published in 1980.

After being almost hunted to extiction a way was found to allow the Cetaceans of earth to full utilize their minds. A thousand years later they have been settled to the world of Cachalot. Man is only allowed on Cachalot at their sufference. However; something is destroying the floating towns. A good book but there are some great leaps taken by the characters and they never really feel fully developed. ( )

In the far future, whales and other creatures from Earth's seas have been relocated to the ocean planet of Cachalot. Something or someone is destroying the few human towns, and the humans and whales have to cooperate to find out who or what. I enjoyed this one. ( )