So we all know that the majority of sea creatures use fins that move either from side to side or up and down to propel themselves.
But our boats don't do that. Our boats use propellers - a rotational motion not based on sea life at all.
That begs the question: how plausible is it for a sea creature to evolve to "spin" in the water as a method of movement?
For example, imagine a fish that had a body containing the shape of a screw propeller (perhaps multiple screw propellers?). It would move through the water by "corkscrewing" itself forwards.
What scenario would result in this sea creature evolving, and as a bonus, how efficient is the corkscrew fish movement compared to the current method of locomotion?
NOTE: Creature must be large enough to be visible to the naked eye (no microscopic organisms allowed) But if you want to say that the creature evolved from a microscopic organism that already uses said approach to movement if you can make it plausible, feel free.
EDIT for clarity: You may assume that there are an abundance of nutrients available. Optimal growing conditions, you can even assume that this guy has no predators.
Explanation for reality check tag: it says "if a concept is realistic in a given context" to which the context here is whatever it needs to be to make it happen