People make jokes but there’s different swimming strategies employed by fish and other marine animals dependent on their anatomy (big dorsal fin etc)

For example:

• whales and dolphins swallow the water in front of them and the force of it pulls them forward
• starfish require the symbiotic assistance of teenage mutant ninja sea turtles to throw them like throwing stars
• speaking of which certain species of sharks discovered in the 90’s traverse are highly complex and sophisticated, traversing only via bikes and roller skates
• polar bears propel themselves like squid using their farts but because they just float atop the water they’re more like the Portuguese man of war which also fires off a brigade of farts