I don’t know if it happens to you as well, but when I see a big cruise ship in person, I always get excited.
It’s hard to imagine how such a big thing can move smoothly and carry so many people.
However, from another point of view, these giants of the sea can also be a bit scary due to their enormous size.
Have you ever wondered what would happen if you approached them with a small boat, or if you swam very close to a cruise ship?
In this case, one of the most common questions is whether the cruise ship could pull you underwater due to the great power of its engines.
I was thinking about that the other day, and since it’s quite an interesting topic, let’s find out together what would happen.
Why Do We Think a Cruise Ship Can Pull You Under?
Hundreds of years ago, sailors were already wondering about that.
Some believed that ships created a sort of whirlpool that sucked underwater all the people who came near.
Sailors were notoriously superstitious and really believed that certain actions could provoke the wrath of the sea.
In modern times, however, this belief has been passed to us by movies and TV series that often show large ships that are capable of dragging everything in their path underwater.
In reality, if we analyze the matter from a scientific point of view, things are very different from what we think.
Wake and Propeller Effects
To understand whether a cruise ship can pull you under, it’s crucial to refer to the basics of hydrodynamics, which studies the motion of fluids.
Cruise ships, despite their enormous size and weight, are designed to move smoothly through the ocean, and for this reason, they displace water rather than creating significant downward forces.
Consequently, the hull’s shape and the ship’s motion mainly generate lateral waves and wake that push water to the sides rather than downward.
What about propellers? Someone might say.
Well, modern cruise ships’ propellers are definitely very strong and create powerful currents.
However, these currents can be dangerous only if you are very close to them. The risk is very small because they are formed exclusively underwater and do not reach the surface.
In addition, they primarily move water backward and not downward. So it looks like the science does not support this myth.
Can Cruise Ships Create Whirlpools or Vortices?
Some people even talk about whirlpools, or vortices, that will be able to pull someone underwater.
They only happen when water rapidly rotates around a central point, which can happen naturally in certain geographical locations but is not typically caused by a moving ship.
Again, the ships’ movements displace water in a more lateral manner, there’s no rotational force.
The Real Danger
After these considerations, we can say that the danger posed by a cruise ship to a nearby swimmer is more about the collision with the ship and the risk of being caught in the wake, rather than being pulled under.
As we said, propellers generate strong water movement and very high waves that can be a danger even to an experienced swimmer.
For this reason, it’s a wise thing to always keep a safe distance from a ship, even from small ones.
In addition, remember to check the specific 5 things you must never do near a cruise ship.
