I came into this series rather ass-backwards, reading the second volume (Cakes in Space) first, then the third (Pugs of the Frozen North), and finally coming back to the first. I found the titles hilarious. It doesn't really matter where you start as it happens, since they're not really sequential or even about the same people. All three have been enjoyable although they're aimed at a much younger audience than I represent.
This one was about this little kid named Oliver, which is becoming a quite popular name choice in the USA over the last couple of years - unlike Sarah, which recently dropped out of the top 100 for the first time since records began.
As it happens, the art for this novel is by a Sarah - McIntyre. She's definitely not unpopular! Oliver has explorers for parents, and he's not happy endlessly wandering the world. To his relief, the parents have finally explored everything, and are moving back to their family home on the coast. Oliver is thrilled.
The thrill evaporates rapidly as his parents are more interested in the islands off the coast - which were not there when they were last at home, than they are in moving things into their house. Poor Oliver is doing this when he realizes that the inflatable dinghy his parents took is back on shore sans parents, and the islands have all disappeared, save for one of them.
It turns out that the islands are the Rambling Isles - rock people who wander the ocean trying to find items to put on their heads to make an impressive sea wig, with which to win the septennial competition among the Rambling Islands.
Befriending an albatross who lives on this one island - which Oliver names 'Cliff', and a short-sighted mermaid, Oliver sets off, transported by the island, to find his parents. The story is delightfully whimsical and inventive, playful and imaginative, and light hearted, with a pair of all-but mustache-twirling villains thrown in. But you might want to steer clear - not of the Sargasso Sea, but the Sarcastic Sea, where the seaweed will make salty remarks about you.
The author is best known for his Mortal Engines series, which I haven't read (yet!), although I enjoyed the movie (unlike most people it seems!). I loved this story, and want to read more of this series.