Blue

well as far as i know its new, i went about 1/4 of the way down the first page of google so yeah.

go to where the black square is on the map and nearby or right there, there should be a road race, drive it with the agency SUV and a driving skill of lvl 4.
-the road race is actually just south of the black square.

go through all of the places till you get to a tunnel that looks too small to go through. when you're there, hold down your hydrolics (b button) and try to go through, you should fit. try to remain in the middle and try to do this near the front. sooner or later you'll get stuck and you can jump around. jump to the left or the right and land in the water.

advatages = getting secret orbs or find out where you left them, you cant collect all, but some. you can blow stuff up from down there.

this is really hard to explain the expirience but yeah.
if you ever get stuck in a kneeling position, just jump and that'll get you unstuck for a lil.

disadvantages = bridges suck, stay away from there unless you're prepared

how to get out = kill yourself, save and exit, extract agent, go to that shipyard thing and jump in the black abyss, sooner or later you'll get reverted.

no matter what you cant go back to normal unless you do that.

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