Footage posted earlier this year on Instagram appears to show a weird shape being carried along by the waves.

The pictures, which can be viewed below, show surfer Ryland Rubens riding the waves in San Diego, Southern California as part of an entry for the Regional Wave Of The Winter competition.

What is that in the water? Image Credit: YouTube / Stay Focus Entertainment

While his performance on a surfboard is certainly impressive, the video ended up attracting attention for a very different reason – if you look closely on the left-hand side, it is possible to see a large object being washed along by the wave.

Some have speculated that the object could be some sort of undersea creature, while others have offered up more skeptical interpretations of the clip – instead maintaining that it is nothing but a large clump of kelp or seaweed that has been dragged up from the ocean floor.

The object certainly does look a little strange, especially given its almost spider-like appearance.

Though the oceans cover more than 70 percent of Earth, just 5 percent of Earth’s oceans have been explored and charted – especially the ocean below the surface. The rest remains mostly undiscovered and unseen by humans.

What got into the frame in the video will probably remain a mystery: whether it was some strange sea creature, kelp, or some other object.

Some comments:

– What the heck is this thing in the water?

– Might be seaweed

– Poor octopus

– Great albatross

– It’s a dirty old swan octopus

– What creature is that…looks a bit scary