Note: by the Digital Sea (wrongly called Digital Void), we mean, here, the part of Digital Ocean which penetrated the virtual worlds. In the series, the heroes call them Digital Sea too. We use this expression especially to separate this small sea from the vast area of digital water that is the Global Network. This fluid circulates through the sieve which is the exit of Lyoko.
The Digital Sea is sometimes wrongly named the Digital Void because when the heroes fall in it, they are digitised forever. The mixture thus probably comes from the expression “Fall into the void”.
The Digital Void corresponds to the “atmosphere” of a virtual world: everything that has no solid (like the ground of the Sectors) or aqueous consistency... Except that we can't exactly speak about atmosphere seeing as gas does not exist on Lyoko. All which therefore appears to us to be like air is really a “Digital Void”
The Digital Sea indicates the aqueous flow which passes under the Sectors. The water of the Digital Sea is only symbolisation.
Two main theories exist as for its exact nature.
- In the Network, we find Data Banks which are immersed in this water. So, the digital water could represent electricity: energy! What circulates in our computers and connects us in a "human network".
- Or then, this water could in fact be a pile of data. The immense amount of data that traverses the Internet and is requested in billions by Internet users. This fact is confirmed by the dangerousness of the Digital Sea. In fact, when a hero falls in there, their virtual body made of data is, in a way, either crushed or scattered, or even gobbled up in this enormous flow of data. That's what makes a fall into the Digital Sea a lethally dangerous experience...to such a point that the heroes would be ready for anything, even to virtualise Laura, to avoid it happening to one of them (episode 13 “Friday the 13th”).
Very few virtual things resist the pressure of the Digital Sea. Some of XANA's monsters were specially programmed to survive it (Sharks, Kongres, later Mantas). However, these monsters stayed in the Digital Sea outside of Lyoko and the Cortex. Ninjas also seem to be able to survive it. Finally, the Skidbladnir was specially designed to resist it.
B) Role in the series
The Digital Sea is an omnipresent danger. It adds spine to the series by creating a certain threat. It is moreover largely the presence of the Digital Sea which renders the instability of the Cortex so dangerous.
As explained above, when one of the heroes falls into the Digital Sea, they put themselves in grave danger of virtual dispersal. Two stages are required to be taken in order to get them back.
The first one and certainly the most delicate: find them in this immense expanse of digital water.
The second, employ a materialisation program as complex as the one that Jeremy used to return Aelita to Earth in the past. It is a process that is terribly more complex than the semi-automatic rematerialisation which takes place after a devirtualisation in Lyoko.
However, the chances of being found and fished out are tiny, hence why the heroes panic every time one of them risks the fatal fall, like Yumi in episode 23 “Jeremy's Blues”. It is therefore necessary to pay attention not to lose one's vehicle above the Digital Sea or to avoid falling there. XANA's monsters sometimes try to propel the heroes there to get rid of them forever (like the residual spectre from episode 19 “The Trap”).
Nevertheless, the heroes also know how to play this game and as XANA's monsters are not immune to the Digital Sea, the heroes sometimes push them in there using diverse tricks (Odd throws Krabe in with a violent shoulder blow in episode 4 “Miss Einstein”).
C) The door to the Network
The Digital Sea was at first only an uncertain and dangerous border for the heroes. From the moment the heroes got the Skidbladnir, they studied this sea and discovered that it is in reality only an arm of the Global Network...
An immensely vaster network that you can discover on its own page.
The Skidbladnir is thus a submarine which allows the heroes to cross the slender barrier that is the Digital Sea before passing through the sieve of Lyoko and taking the battle to a much vaster territory.