It’s amazing how some people can recognise old old books from just a few snippets of description! I have two books I can’t name; both of them read during very formative years and which made a big impact on me, but I can’t for the life of me remember their names or find them anymore. Both were read around 1981/ 82.
The first is a science fiction book; all I really remember is the main character was a boy who befriended a huge, articifical (electronic) whale, perhaps a blue whale, and rode the oceans between submerged (but living and functioning) cities.
The other book was a travelogue with some black and white pictures. It was written by a man who had emigrated to a sunny archipelago (I’m thinking the Maldives or the Pacific islands off New Zealand). To make a living he joined the crew of a shark fishing boat (of which there were a few), eventually captaining one himself. They’d lure the sharks to the surface somehow (without any automation) and spear them as they came alongside.
I recall him observing that you had to be fast and determined with the spear because within a split second the shark would begin thrashing and the spear osscillated so quickly it had broken many men’s arms into splinters, ending their careers. The other recollection I have is of his boat being becalmed one day. As there was no fishing his crew dared him to swim a lap around to boat. He felt they were quite safe and jumped in. He made the full circuit and just about pulled himself up on the bowsprit when two sharks who had been barreling upwards broke the water just beneath him. It was a real tale of derring do and adventure and a brilliant read, in a Boys Own kind of way.