Give Now

A Moment of Science

The Physics Behind A Ship’s Wake

There's physics and science behind a ship's wake.

You might expect a ship’s wake to be more agitated than the surrounding water. Instead, it’s a smooth path through the waves that can extend for miles behind the ship.

How Come?

The wake starts out smooth because the passage of the ship destroys whatever wave patterns were there before the ship came through.

The reason it stays smooth has to do with tiny organic molecules–such as decomposed plankton–on the surface of the water.

There are always some organic molecules on the ocean’s surface, but as the ship pushes along, it plows these molecules to the sides. This leaves the wake something like a winter road that has just been snow-plowed, with piles of snow on both sides of the road.

The center of the wake is relatively free of organic molecules, but the two sides each have an accumulated pile-up. These stretch behind the ship on either side of the wake like ribbons.

Keeping The Wake Smooth

Well that’s interesting, but how does this keep the wake smooth?

It turns out that a thin ribbon of organic molecules on the surface of water is really good at suppressing small waves. These two ribbons, on either side of the wake, act like guardrails, preventing small waves from entering and crossing the wake.

So that’s why the wake stays so smooth and gloss-microscopic ribbons of decomposed plankton!

Stay Connected

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from A Moment of Science:

Support for Indiana Public Media Comes From

About A Moment of Science

Search A Moment of Science