The Sea is the vast structure that contains an uncountably infinite number of Reality Bubbles. Our local Reality Bubble is called Isolation.
The Sea appears to be a vast, translucent black-tinted "void" with Reality Bubbles spread out evenly. The further you try to look, the blacker and darker The Sea seems to get.
The Sea really isn't a void. There is a liquid substance that fills up the space between the Reality Bubbles and cushions them in case there is a major disaster, like the extremely rare case in where a Reality Bubble pops and launches verses everywhere. This material seems to very resistant to extreme temperatures, and cannot be forced to change states of matter. It also is nigh impossible to break it down with corrosive acid and molecular bond-breakers. It has also been found to be very hard to travel long distances in it. This material has been dubbed "Overpowered water".
There have been many attempts to escape The Sea. Most failed, due to the infinities upon infinities upon infinities of Reality Bubbles and endless overpowered water, which makes traveling even harder. However, on one occasion, a omni god, along with many other omni gods, glitched out of The Sea. They landed in The Loop, the place you go if you somehow escaped The Sea. They then got trapped there for all eternity.