What would happen to the sea level if all boats where taken out of the ocean?

Answer 1

First, we look at what actually makes a boat float...
The hull shape "contains" a volume of air on one side, and displaces an equal volume of water on the other (more or less - actually, it displaces the amount of air plus the amount of material in the hull itself).

Second, we look at how vessels are rated ... that is, the concept of "tonnage".
What this really means is NOT the amount of payload it can carry (like how a pickup truck is called a half-ton because it can carry around 1000 lbs payload). Actually, it refers to the mass of water the hull displaces when the vessel is fully loaded.

Then we need to look at the volume of water required to achieve that mass ... and spread it out over the whole surface of the globe (at least, the surface covered by ocean).

Taking just the top five ports (Shanghai, Singapore, Rotterdam, Ningbo, and Hong Kong), the annual tonnage through the ports is a combined 1734638000 metric tonnes (3823142152000 lbs).

The average density of seawater is 1027 kg/m3 (0.0371 lb/in3).

So ... (displacement) / (density) = (volume)
1743638000 tonnes (17436638000000 kg) / 1027 kg/m3 = 16978225900 cubic metres.

Now, a cubic metre is equivalent to 1000000000 mm3. The area of the oceans is approximately 335258000 km2 (335258000000000000000 mm2).

(depth) = (volume) / (area)
= 16978225900000000000 / 335258000000000000000
= 0.0506 mm

So if we lifted all those vessels out of the water, we'd raise the average level of the oceans by 0.0506 mm ... approximately 0.002 inches.

Answer 2

it would drop by such a small number it's meaningless......think of it this way....take a grain of sand out of a swimming pool....there's a difference but a pretty small one, right? There's 3 times as much salt water ( in surface area) as land on this planet, and in volume its probably more like 10 to one........so the difference is probably more like taking one brick out of Lake Michigan.....

Answer 3

The sea level would drop slightly -- not enough to be measurable. Call it "negligible."