How much ocean water is currently being displaced by ships?

According to Statista, as of January 2017, there are approximately 52,000 ships currently operating in the merchant fleet and 11,000 of these are considered bulk carriers.

How many ships are there in the world? The number of ships in the world exceeds 50,000: As of January 2017, there were 52,183 ships in the world's merchant fleets. General cargo ships are ranked as the most common type of ship in the global merchant fleet, accounting for about a third of the fleet: There were almost 17,000 such ships in the merchant fleet as of the beginning of 2017.

According to Wikipedia, the Batillus class bulk carrier, unloaded, displaces 77,300 tonnes of water and 630,962 tonnes when under a full load.

Assuming a range between 850,300,000 and 6,937,612,000 tonnes of displaced water, what would be the acceptable average range of water that could be displaced by the merchant fleet during daily operation?


According to Ocean's Depth and Volume Revealed - Live ScienceOcean's Depth and Volume Revealed - Live Science, the ocean's volume is approximately 1.332e+18 cubic metres

A group of scientists used satellite measurements to get new estimates of these values, which turned out to be 0.3 billion cubic miles (1.332 billion cubic kilometers) for the volume of the oceans and 12,080.7 feet (3,682.2 meters) for the average ocean depth.

How much does that displaced water raise the sea levels?

a reply to: wtfatta

That dispersed water raises the sea levels by a number so small, I will confidently declare it zero.

I challenge anyone to disprove me with observed evidence and data.

It may seem like a lot of "displacement" but remember that adding pressure to the ocean will "lower" the ocean bottom as well as "raise the water at the top"

Given we don't have ships the size of Rhode Island, and the Earth is 2/3 water by surface observations...

All ships combined would probably not be a large state, if even larger than Rhode Island, at all.

Finding the actual displacement with scientific equipment, would require instruments so precise and therefore expensive, that I would doubt the ability on any here at ATS to prove my zero rounding incorrect.

You would need research University level equipment to gather that data and rule out all other ocean level factors.

(The moon probably raises our global ocean more, than all of our ships do.)

Throw 200,000 ants into an Olympic sized swimming pool. Then measure how much the water went up.

That should give you a rough idea.
Probably not much.

PS- there is a noisy public pool close to my house, we start there.

a reply to: wtfatta

Great thread topic!
A. 42

Are you being serious?

How much does that displaced water raise the sea levels?

Would not even be noticeable.

264 billion gallons

Northern and Southern ICE sheets displace some.

Sure ship obviously do to create buoyancy.

Figure average depth.

Figure the Earth isn't a perfect sphere, but appears as one because of rotation as an optical illusion.

It's a question that has no answer.

originally posted by: Archivalist
a reply to: wtfatta

That dispersed water raises the sea levels by a number so small, I will confidently declare it zero.

I concur; however, I'm still curious what the "rough" number would be. More to the point, I'm curious what amount of displacement has occurred as a result of ships, artificial land masses like Dubai's palm tree, etc. On that note, I still the the increase is negligible. Like Schrodinger's cat, I'm curious, but it's a 50/50 on whether it'll kill me

a reply to: wtfatta

Seems like you were almost there. If we take the middle of your range of displacement => 3.9e9 tonnes of water, and the fact that 1 tonnes of water = 1m^3 (actually 0.99972m^3). The amount displaced relative to the total ocean size of 1.3e18m^3 is:

3.9e9/1.3e18 => 3e-9. So the displacement is .000000003 times the size of the ocean.

I love questions like these. We all know it's a very small amount, but fun to calculate how small.

originally posted by: tvtexan
Throw 200,000 ants into an Olympic sized swimming pool. Then measure how much the water went up.

That should give you a rough idea.
Probably not much.

PS- there is a noisy public pool close to my house, we start there.

Yes but are they angry ants?

originally posted by: Metallicus
Are you being serious?

Yes lol. Is it wrong to ask? Should I be shunned for asking? Did you assume this is an attempt to prove or disprove something "climate changy" or did you realize it's an actual question, had nothing to offer, but still felt the need to speak? That's fine too. I'm just looking for clarification.

originally posted by: bluesjr
a reply to: wtfatta

Seems like you were almost there. If we take the middle of your range of displacement => 3.9e9 tonnes of water, and the fact that 1 tonnes of water = 1m^3 (actually 0.99972m^3). The amount displaced relative to the total ocean size of 1.3e18m^3 is:

3.9e9/1.3e18 => 3e-9. So the displacement is .000000003 times the size of the ocean.

I love questions like these. We all know it's a very small amount, but fun to calculate how small.

Thank you for the answer and insight!

a reply to: wtfatta

At what point does a ship cease being a ship and is merely a boat?

Why do the calcs not account for tinnys and jetskis and canoes and small to medium pleasure craft?

Whats the difference between a ship and a boat?

What about dock water density and fresh water rainfall effecting sea water density?

I remain sceptical we will flood all the landmasses with vessel displacements - even if all the ships had all the fat people on them.

originally posted by: Sublimecraft
a reply to: wtfatta

At what point does a ship cease being a ship and is merely a boat?

Why do the calcs not account for tinnys and jetskis and canoes and small to medium pleasure craft?

Whats the difference between a ship and a boat?

What about dock water density and fresh water rainfall effecting sea water density?

I remain sceptical we will flood all the landmasses with vessel displacements - even if all the ships had all the fat people on them.

I agree lol. It's highly unlikely we could produce enough of a displacement to flood a majority of the landmasses let alone all of them. I am interested in including all of the variables you mentioned and more; however, for this medium, I feel that it would be far too granular. That's also why I didn't include the water displaced by artificial land masses.

If the ocean was perfectly calm, and you could make a measurement before and after adding the ships, the total measurement would be less then half the diameter of a frogs hair.

a reply to: Sublimecraft

Why do the calcs not account for tinnys and jetskis and canoes and small to medium pleasure craft?

And these.

a reply to: abeverage

Hell yes they will be angry after being thrown in a public pool!

Think of all the urine!
Sheeesh!

originally posted by: bluesjr
a reply to: wtfatta

Seems like you were almost there. If we take the middle of your range of displacement => 3.9e9 tonnes of water, and the fact that 1 tonnes of water = 1m^3 (actually 0.99972m^3). The amount displaced relative to the total ocean size of 1.3e18m^3 is:

3.9e9/1.3e18 => 3e-9. So the displacement is .000000003 times the size of the ocean.

I love questions like these. We all know it's a very small amount, but fun to calculate how small.

And since the average depth of the ocean is about 12,000 feet, if you multiply that by that .000000003, you get something like 120 nanometers, or a micrometer at the most. So, all those ships raise the level by a fraction of the width of a hair.

That's crazy, interesting question OP.


Edit: On closer calculation it's about 11 micrometer.

a reply to: wtfatta

I don't know but when the container ships pass by the beach it makes big waves and it's about a quarter mile off the beach in the channel.
I saw an aircraft carrier go by the other day. It was even bigger than the container ships but I wasn't on the beach yet I was driving to the parking lot.
I was at old point comfort across from the port of Norfolk and the naval station and shipyard.
I've seen everything from tough little tug boats to garbage scows to submarines. Ive seen a hospital ship, a P.T. boat, a gorgeous hugh luxury yacht that made my tongue hang out. You name it. I spend a lot of time at the beach. I can't say how much they displace but they sure make it move.

Hmmm I wonder if this is part of why sea levels are rising...

Good OP.

originally posted by: abeverage

originally posted by: tvtexan
Throw 200,000 ants into an Olympic sized swimming pool. Then measure how much the water went up.

That should give you a rough idea.
Probably not much.

PS- there is a noisy public pool close to my house, we start there.

Yes but are they angry ants?

Can you imagine the ruckus with how many anteaters we'd have to throw in the pool to clean it up?

Some people just don't think ahead!