Boaters captured the gruesome scene of a dead whale bobbing in the ocean, letting out ‘one final burp’ before exploding- releasing blood and rotten guts.

The ‘National Geographic Moment’ was observed off the coast of California by a group of whale watchers who spotted what appeared to be a lifeless humpback in the Pacific Ocean.

The boat pulled alongside the carcass spewing water from its mouth and gas trapped in the abdomen vacated, triggering an eruption of its internal organs – including its spleen, small intestines and stomach.

The event allowed the dead whale to sink slowly to its final resting place on the deep sea floor.

The gruesome video is making waves on the internet after being shared by the popular animal Instagram account Nature Is Metal.

The clip was first posted on the Ozzy Mans Video Licensing account, which recredits Shayne for capturing the moment.

‘These violent detonations are unique to whales, as the vast majority of decomposing animals can not keep all that built-up gas inside after they’ve passed away,’ the caption on Nature Is Metal reads.

When an animal dies, bacteria inside the carcass produce methane as part of the decomposition process.

If the gas is not released from the body, it gradually builds up until it has no choice but to bust through the animal’s carcass.

Methane gas builds up in the animal’s main body cavities, causing it to bloat – a sure sign an explosion is on the horizon.

‘Since the build-up of gas will eventually reach capacity and find the path of least resistance for escape, the only way to prevent this is to perforate the whale’s skin before it detonates on its own,’ according to Nature Is Metal.

The humpback in the video began to sink after the gas was released, but its body is too large that it will likely land on the seafloor intact.

National Geographic reports that entire communities will grow around the carcass.

Swimming scavengers will first appear, including sharks, which will tear off the tissue and break up the body.

Then, creatures that feast on bones will arrive to finish the job – but the entire body will not disappear for at least another 30 years.

In the video, shot in January, the whale watchers think the sea of red blood was because of a white shark, but that idea was quickly forgotten when the animal’s organs began to flow out from its body.