59-year-old Rudiger Koch is currently living in a submerged capsule off the coast of Panama, having started his challenge on September 26.

He’s now around half-way through his challenge and hopes to make it to 120 days, meaning he’ll resume his normal life on January 24.

The current Guinness World Record for longest time spent living in an underwater fixed habitat is held by US native Joseph Dituri.

Dituri lived in a capsule just off the coast of Key Largo, Florida, last year for 100 days.

But Koch wants to beat this and plans on remaining submerged in his 322-square-foot living space for 120 days, taking him through to the New Year.

He has everything he needs in there: a bed, toilet, TV, computer, an exercise bike and internet.

Koch is missing a proper shower, however.

Koch’s capsule is just 322-square-foot big (MARTIN BERNETTI/AFP via Getty Images)

He has access to the rest of his team via a vertical tube that’s connected from his capsule to another chamber perched above the waves. From this, he receives food and curious journalists have been sent down to visit him.

His wife and kids have also been visiting him while he undertakes the unusual challenge.

Speaking about what it’s like living down there, Koch told AFP: “In the night, you can hear all the crustaceans.

“There’s the fish out there, and there’s all that stuff, and that wasn’t here before we came.”

His 120 days will be up on January 24, 2025 (MARTIN BERNETTI/AFP via Getty Images)

In addition to breaking the current Guinness World Record, Koch hopes that his test could make waves elsewhere.

“Moving out to the ocean is something we should do as a species,” he said.

“What we are trying to do here is prove that the seas are actually a viable environment for human expansion.”

While some people would get cabin fever from being in a small space for such a long period of time, Koch insists he doesn’t mind his current living arrangements.

The experiment is being conducted off the coast of Panama (MARTIN BERNETTI/AFP via Getty Images)

“I don’t feel like I’m suffering down here, not at all,” Koch said.

“That hardest is probably, sometimes I would like to go diving.”

Four cameras are monitoring Koch while he’s submerged which will act as evidence to prove how long he’s been down there, as well as give his team the chance to monitor his health.

As to what Koch is going to do when he resurfaces next month, he says his first port of call will be getting a ‘real shower’.