I've been trying to recall the name of a book for years, here and there and not very seriously, but now it's driving me crazy. When I was a freshman in highschool I read a fairly short science fiction novel that left me with a feeling that's really stuck with me, but that I remember almost no concrete details of. I know that it was published quite a while before 1998, my feeling is late 70's or early 80's. The protagonist drifted through worlds, I think, and he likened himself to a jellyfish, it may've been a theme. I do distinctly remember one scene though, where the man is walking on a crowded street, and the police detect that someone has cancer, tracks them down amid the crowd and executes them right there on the street.
This scene from Ursula K. Le Guin's The Lathe of Heaven is a good match:
The crowd bumped around the pair, some stopping to watch, others pressing on toward the Palace of Sport. “This is a Citizen’s Arrest, passersby please take notice!” the tall man was saying in a piercing, nervous tenor. “This man, Harvey T. Gonno, is ill with an incurable malignant abdominal cancer but has concealed his whereabouts from the authorities and continues to live with his wife. My name is Ernest Ringo Marin, of 2624287 South West Eastwood Drive, Sunny Slopes Subdivision, Greater Portland. Are there ten witnesses?” One of the witnesses helped hold the feebly struggling criminal, while Ernest Ringo Marin counted heads. Orr escaped, pushing head-down through the crowd, before Marin administered euthanasia with the hypodermic gun worn by all adult citizens who had earned their Civic Responsibility Certificate. He himself wore one. It was a legal obligation.
The main character doesn't move through worlds, rather he edits the world when he dreams. But there are frequent sea-life analogies, especially sea turtles and jellyfish.
Ch. 1 (opening paragraphs):
Current-borne, wave-flung, tugged hugely by the whole might of ocean, the jellyfish drifts in the tidal abyss. The light shines through it, and the dark enters it. Borne, flung, tugged from anywhere to anywhere, for in the deep sea there is no compass but nearer and farther, higher and lower, the jellyfish hangs and sways; pulses move slight and quick within it, as the vast diurnal pulses beat in the moondriven sea. Hanging, swaying, pulsing, the most vulnerable and insubstantial creature, it has for its defense the violence and power of the whole ocean, to which it has entrusted its being, its going, and its will.
What will the creature made all of seadrift do on the dry sand of daylight; what will the mind do, each morning, waking?
It's a fairly short novel first published in 1971.