What's the biggest wave you've ever seen?
Seven metres.
We measure waves close to ten metres.
About 14 metres.
Bit taller than 20 metre.
Wow. That's a big wave.
Nah, nah.
I'm in awe and I'm scared of that.
These giant walls of water aren't tsunamis.
They're not caused by earthquakes,
but they're just as deadly.
So, what causes a rogue wave?
And can they explain the mystery
of the Bermuda Triangle?
Hi Justine.
So, you surfed a wave taller than 20 metres?
That's about the size of a building.
We scared at all? Were you nervous?
Sometimes, yeah, it's like... scary afterwards
because when you see the picture and the footage,
like, "OK, wow. That was huge!"
But despite its mammoth size,
this wave isn't considered "rogue".
Rogue waves of waves that are over twice
the height of all the waves surrounding them.
So, if we have waves that are two metres high,
on average, a rogue wave is defined as something
that's more than four metres high.
That day, most waves were hitting around
the 15 to 18 metre mark.
So, Justine's 20 odd metre beast wasn't double.
It wasn't rogue.
Imagine calm seas and then out of the blue,
an eight-storey tall wave.
That's a rogue wave.
It's the unpredictability that makes them so dangerous.
There are incidents reported
where a ship has been smashed by waves,
the windows has been smashed out by the wave.
The engine stop and then the ship is in trouble.
Rogue waves have been observed
by mariners for centuries.
They've seen these rogue or freak waves
and reported on them as they've come back.
But it wasn't until January of 1995
when we actually observed the first rogue wave.
And it was observed at the Draupner oil platform
off the coast of Norway.
The waves were about 12 metres
and the rogue wave that was recorded was 25.6 metres high.
Wow. That's... that's a big wave.
That's an enormous wave.
And it's really the biggest rogue wave
that has been recorded to date.
So, what causes rogue waves?
One way is around having multiple wave trains,
so a series of waves traveling and interfering
with each other and adding and subtracting together.
So, if you imagine you have two waves
that are one metre tall each
and they happen to occur and overlap,
then you'd end up with a wave that was two metres tall.
The convergence of two waves is known as "linear" behaviour.
The model for this theory
suggests rogue waves should be rare,
but they're not.
So, some scientists theorise
"non-linear" behaviour is also at play.
In the non-linear water,
this wave will start to talk to each other
and one of them will start asking a little bit of energy
from its neighbour.
And then, that's not enough.
We will ask energy to the other neighbour,
That's not enough. Enough is never enough.
So, we start getting energy from all different neighbours.
Non-linear models help explain chaotic systems,
like how weather forms
or how water can suddenly go rogue.
And this phenomenon, which is basically
an instability process, will occur very quickly
and very quickly, will disappear.
So, the wave field will go back to normal again.
Meaning rogue waves are chaotic and hard to predict.
So, could these agents of chaos be the answer
to the Bermuda Triangle mystery?
As far as I'm aware, there aren't actually any more
shipping disappearances in the Bermuda Triangle
than anywhere else around the world,
relative for its area.
There is no evidence for that?
In terms of physics and science that rogue waves,
as we know them nowadays,
can in principle occur everywhere.
The straight answer is everything is possible.
(LAUGHS)