What word best describes the sound made by an object passing through water for a prolonged period of time? "Whoosh" and "Splash" both come to mind, but neither really describes what I'm thinking of of. "Whoosh" sounds too airy and "Splash" connotes a sudden, loud, impact with a liquid as opposed to a gradual passage through it.
I think "swish" is the right onomatopoeic word for this. It is usually used for the sound of movement in air but it applies to water as well.
swish vb 1. to move with or make or cause to move with or make a whistling or hissing sound
swish sound of an object moving through air or water
Examples from books:
The Heart Mender by Sally Streib:
Silent Victory By Clay Blair
North Star of Herschel Island - the Last Canadian Arctic Fur Trading Ship By R. Bruce MacDonald
One option is the onomatopoeic word sploosh. It appears in a number of published works going back many decades. For example, from Kenneth Graham, The Wind in the Willows (1915):
Greatly alarmed, he [Mole] made a grab at the side of the boat, and the next moment — Sploosh! Over went the boat, and he found himself struggling in the river.
From Amazing Stories, issues 7–12 (1940) [snippet]:
Sploosh! The unseen surface [of the water] flew up at him like a floor. He pierced it as squarely as a plummeting bomb. At the risk of breaking his back, he cut his swift course upward ; and luckily, so, for he scraped rocks that projected from the bottom.
From Carter Dickson, Night at the Mocking Widow (1950) [snippet]:
... a sudden occasional gush like a water spout, kept it always fresh. To the crowd, pressing along the planks on either side, it was the biggest hit of the bazaar.
"Ol' parson do have some good notions, don't 'e? One wrong step, and — sploosh!"
"Ah, ol' parson's all right!"
""Like me to chuck 'ee in, Gert?"
From Life Around Us (1964) [snippet]:
Young seals sometimes slide down a smooth sloping sandbank and plunge headfirst into the sea with a sploosh. Down under the water they go—swimming and tumbling, and chasing each other in circles and somersaults.
From Mademoiselle, volume 62 (1965) [snippet]:
To a non skin diver, life in the company of an enthusiast is very much like living with a bubble. One minute he is with you in the boat or on the rock, then, sploosh!, into the sea he goes—and the only record you have of him for hours is an aerated movement on the surface of the sea.
From Texas Game and Fish, volumes 24–25 (1965) [snippet]:
Familiar sounds along the banks of the Colorado River in Central Texas often have been spiced with an occasional "zing— sploosh!" A brilliant day centuries ago might have beckoned Indians with their bows to fling their arrows into the into the river after a fat fish, and modern-day archers in the area have rediscovered this challenging activity.