Siphons of octopi, squid, and cuttlefish jet through the water with directional control via jet propulsion.
Amphioctopus marginatus. This small octopus was found on a night dive off the Northern coast of East Timor approximately 40 kilometers West of the capital Dili
"Octopuses, squid, and cuttlefish have a more sophisticated version of jet propulsion. They expel water through a moveable tube called a siphon, which combines power with directional control." (Downer 2002:17)
Book Weird Nature: An Astonishing Exploration of Nature's Strangest BehaviorFebruary 3, 2002 John Downer