How to Sink a Ship With Bubbles

Bubbles are the last of all the things on the high seas that anyone would suspect could bring down a ship. But, as it turns out, they can.

One way for bubbles to turn sinister is if they lower the density of the water surrounding the ship. Ships float because of Archimedes’ Principle: they displace enough water to compensate for their weight. But if the density of the water lowers, they’ll need to displace more of it, and sink lower into the water. If there are enough bubbles, this can sink the ship.

This isn’t just theory either, it’s actually been done. Researchers sunk a series of PVC tubes with tiny holes in them and pumped air through them. A boat stationed above the tubes sunk in a few minutes. This isn’t too realistic as the boat was stationary, and the bubbles tend to force things outward. It’s very improbably that millions of tiny bubbles can sink a ship.

But what about larger bubbles? The other way that bubbles can sink ships if is one large bubble hits the ship. This can place a huge force on the hull, violently cracking it, or tipping it over in a matter of seconds. This has been accurately simulated in scale lab tests.

But does this ever actually happen in nature? Actually, it can. There are huge deposits of methane hydrates, frozen methane gas, all over the bottom of the world’s oceans. A landslide or earthquake could release massive amounts of methane from these deposits, creating huge bubbles that could take down any ship floating above.

As these bubbles continue to ascend in the atmosphere they can even wreak havoc on airplanes. Methane is far less dense than air, so any plane that hit a methane cloud would instantly drop. But the altimeter, which reads altitude based on air pressure, would shoot up. A confused pilot could easily push the nose down based on the altimeter reading, and head straight into the water.

Methane can also kill combustion engines at concentrations as low as 1%. Not to mention that methane is flammable, and if the bubble had a sufficient concentration, it could catch fire or explode.

But how often does any of this happen? All indications say that it’s pretty rare. But it’s the most likely cause behind many famous vanishings at sea, including many in the so-called “Bermuda Triangle”. We know these hydrates are out there, we’ve seen them bubble, we know a landslide could trigger a huge bubble, we know that the bubbles can be deadly. The only conclusion that we can make is that this is a real, if unlikely, threat. So next time you’re out to sea, watch out for killer bubbles.