Head Above Water is the fourth Story Mission of Shadow of the Tomb Raider and still a part of the game’s prologue. It features a bit of traversing under time pressure.
Quest Giver: automatic
Requirement: having finished Hunter’s Moon
Trophy: Recipe for Disaster
Get to Higher Ground
So, it seems that Lara has caused a Tsunami of sorts with removing the Dagger. Time to stay alive for now!
For the first part, we just need to navigate in the water while trying not to hit anything. Quite easy actually.
Eventually, Lara will be pulled underwater and has to dive out of her entrapment and through a flooded supermarket – which also features an air bubble which you should make use of.
After breaking through the door seen above, Lara needs to swim through a bus and break its back window to finally reach the surface again.
Now it is time for some face-paced traversal. Jump on the white truck in the water and onto the Billboard behind it,
walk on top of the Billboard and over the crane, grab the lantern while jumping
and continue towards the burning house in front of you.
Reaching that wall nets you the Recipe for Disaster-trophy.
Climb a bit to the left and jump onto the brown sign to continue.
Once you have reached the corner, you just have to make another small jump over the gap and climb to the roof next to the burning window.
Now, the final cutscene of this short mission will play. Lara is relieved to see Jonah again,
and suggests to immediately go after Trinity. This selfish behavior makes Jonah a bit angry, as he wants to help the wounded people around them.
For all other main missions check out the full Shadow of the Tomb Raider Walkthrough.