Oh, hello.
I'm Gavin.
This lovely slow-mo video.
We're going to be recreating the effects
of a depth charge against a submarine
and obviously filming it at insane frame rates
not a real submarine, they're quite expensive.
So we're going to use a scale model that fits
inside this here fish tank.
This video is sponsored by GoPro
for all the slow-mo footage shot from outside the tank.
We'll be using Phantoms as normal
but to get shots from inside the tank in the danger zone
we'll be using the GoPro Hero 9 black
because it's very rugged and you
can get a waterproof housing for it.
We actually had a GoPro Hero 1
rolling during our very first shoot and have
used them countless times over the last 10 years.
And we've put them in some
pretty dangerous situations, such as crash.
Bang.
Hot.
Wet.
And up.
So, I'm very thankful that
they're sponsoring this video today.
Why don't we fill the tank and get going?
Okay, here we have the sub
in the tank for the first experiment.
I'm going to be placing a depth charge just
in proximity to the sub see if
it does any damage with just the shockwave.
There's an air bladder inside that might be ruptured
and it's also keeping it buoyant.
We will be rolling at 200 frames a second on this GoPro.
And I preset all the settings with my phone.
However, WiFi doesn't work through water.
So, once we submerge.
I'll have to frame it using the screens built in.
Thankfully there's one on the front and the back
so I can get the correct framing that actually
looks pretty epic there looking straight down the sub.
So if we put the depth charge in front of it on this side
we should be able to see if it wobbles the sub in place.
On the outside of the tank I'm going
to be filming this at 28,500 frames a second
on a Phantom, which means I'm about
to turn on some very bright lights.
Okay, we're now cooking under the hot lights.
GoPro is running at 200 in the tank.
The Phantom Flex4K is running at a thousand and
for the nice tight explosion shot, we're running at 28,500
which should be fast enough, but we may go faster.
The depth charges hanging just in front
in the middle of the sub, and we're ready to pop it.
Three, two, one, bang!
Nice little puff.
Whoa, you can just see the shockwave bouncing around
off that glass just vibrating everything.
It actually moves insanely fast.
If I just put an arrow that marks the travel
of the shockwave as it dislodges bubbles
you can see how quickly it moves.
Even dislodging bubbles from the
GoPro housing itself at 28,500 frames a second.
This is now over a thousand times slower than real time,
whoa, just love that expansion of gas.
Just carving out an empty sphere in the middle of the water.
You can see that the way the charge separated.
We actually lost a lot of energy there
because the bottom sort of shot off
the pressure of the surrounding wall.
Now close that back up, which means
that not only is there a shockwave traveling
around that tank from the original explosion.
The moment it all slams closed it will release
another shockwave which will bounce around in there.
Just vibrating every single joint of this submarine
it even popped open the little escape patch.
Love it.
Okay, so now we're going to more tightly wrap that charge
and hopefully give us a bit more punch
by wasting less energy downwards.
For those curious as to why
I'm blasting this with so much light you
may remember from the original underwater video
in order to get any detail in the explosion itself.
I had to stop the lens down so much
that everything else was almost pitch black.
And I wanted to capture detail
inside the explosion as well as the submarine itself.
So by hitting it with much more light, I can stop the lenses
down so that the explosions aren't just pure white
and the submarine isn't pure darkness.
I'm now slightly closer on both cameras just to
really see the, the meat of the explosion.
Sensor it up there.
Okay, here we go.
Three, two, one, bang!
Woo.
Blew the top off, but the air bladder still intact.
Very interesting one.
Oh, I saw some great frames in there.
I think I saw the thumbnail.
Let me find it.
Let me see the thumbnail frame.
Yeah, I think that's the one.
I think that's the thumbnail.
Ooh, yeah just through the entire look
of those vortices it's because it's threw
the entire explosion forwards into the glass.
It's always just so interesting to
see explosions at such a leisurely pace.
You can see it's thrown in the front of that
out of focus just because it came so far forwards
and here you can see the granules, the powder
from the new explosion, actually moving with such velocity.
They've escaped the original explosion sphere
and now they're being sucked back in as it
all implodes and shoots forwards.
Just an absolutely devastating effect on
all the joints of the sub.
We're only about a foot underwater here
but the camera is actually waterproof
out of the box to thirty three feet.
That depth charge looked great.
However, I really want to bust the air bladder inside.
So we're going to do now same depth charge
in the same place.
However, there are now three charges
on the top to hopefully blow the top
of the sub open and there's one
on the inside so that the bag definitely breaks.
So we should see a nice bubble
of air and maybe it will sink.
I now have a second GoPro mounted on the bottom.
This one is recording in 4K
not slow-mo just to get the sub sinking.
If it does sink.
This one still rolling in slow-mo 200 frames a second
is now mounted to the sub itself and mounted extremely close
to the charges. Should get some lovely footage
but we'll probably go flying, thankfully
because it's such a rugged camera.
The footage will be saved in theory
Three, two, one. Bang!
Whoa!
Can't wait to see the footage on that.
Where's the GoPro landed?
Oh yeah, it did.
Okay. It flew off, but let me see
if I can see if it's rolling.
I still see a flashing red light and that's very good news.
Whoa, those charges on top of meaty
just sent a shockwave all the way down the end
snapping the sub and it's rear joint.
And the fact that you can see the surface of the water
it really shows you how much that glass
is wobbling back and forth.
Whoa. So the, the big shot is on top
went off before the depth charge on side.
And you can see tiny cavitation bubbles working their way
from right to left as it travels
just tearing up that plastic of the sub.
Speed it up and back and forth that you can see its travel.
It also shot a lovely bubble ring
from that hole directly below the charge.
So the air bladder inside definitely popped
but the shockwaves are just bouncing the air
around inside and the depth charge there it
must've been waterlogged because
pretty much just coughed instead
of its usual explosion, GoPro still on there.
Oh, there it goes.
Yeah. The air took a long time to come
out just because the shockwaves were bouncing it around
inside sending some of it down.
Some of it left and right, mental.
Now let's see if the GoPro saw anything
useful before it was chucked.
Oh yeah, oh yeah.
We saw some good frames there.
No issues with the footage.
A lot of times that I've put cameras near massive shockwaves
like that you will get artifacts and glitches
but I didn't see an issue with any of those frames there.
Whoa, that's the other one landing
that shockwave was so powerful.
It actually jumped the very heavy metal bar
keeping the sub way down.
Well there, we have it, some lovely looking footage
and as expected, the GoPro's got chucked all
over the place especially the ones I mounted to
the submarine itself, but they all survived.
Got the footage off all of them and
did a damn good job in my opinion.
If you care about my opinion on this camera
the things I like about it over
the previous versions is mainly this clip.
I'm not sure when this started my previous GoPro
you need an external housing to mount it and stuff.
I love that it's built into the camera body now.
And the front screen is great when you can't get
around the back of the camera.
If you want a Hero 9 black of your own
go to gopro.com/slowmoguys
Big old thanks to GoPro for sponsoring this video.
Even bigger thanks to you for watching it.
If you like Slow Mo in general
make sure you subscribe and I'll see you in the next video.
Thank you very much for watching.