Maneater

This DLC adds a bunch of time trials to the list of open world activities. You will be required to complete around three time trials during the DLC story missions in the new region, but upon returning back to the base game regions, you'll see many more time trials added to your map to complete. Each one involves swimming through a series of rings, getting to each one before time runs out. 
 
There are three main aspects to these time trials:
 

1. Moving fast enough to actually reach each ring before time runs out. I found this to be a non issue. You can apparently equip the entire Shadow armor set to boost your speed, but I did every single one with my regular gear (Shadow Teeth and Bone everything else) thanks to the fully upgraded Brutal Muscles. This gives a 30% boost to swim speed and it made reaching each ring trivial. Just press and hold until your sprint ends, then release and press and hold it again. 
2. Moving from ring to ring on land. This is necessary in a handful of time trials. I never had any issues with having enough breath (again, with my normal gear above, plus being Mega evolution so having maximum lung capacity). I'm sure you're used to it by this point, but the fastest way to move forward on land is to just mash to keep lunging forward. 
3. Jumping up through high rings, especially ones on a bridge. This is really the only difficult part of time trials, in my opinion, since almost every single one ends with a ring high up on a bridge, and many have other high rings through in before the end. This is the only place where some skill is required. 

There are two methods of jumping up high enough to reach those high rings:
 

• The first is the one the game essentially wants you to do, which is breach out of the water from below the surface. 
• The second is jumping up while "knifing" on the surface. 

Both work pretty similarly, but it's critical to know what buttons to use to get the necessary height. Starting with the first method, while underwater you're going to need to angle yourself properly to jump up and out and still move toward the ring so you clear the bridge. This is pretty tough to do since you can't see much above the surface, and why I opted for the second method below. Once you're lined up, press and hold to dash towards the surface. Right before you get to the surface, press to jump and breach through the surface (you can let go of at this point). Then, in mid air, press again to double jump. Then press to lunge further. So it's to dash, to breach, to double jump, then to lunge. This will guarantee you the height every time when done properly, but getting the right angle can be tough to judge while underwater. 
 
The second method is to jump from the surface of the water instead of starting underwater. The inputs are almost identical minus the first to dash. From the surface, press to jump off the water, again to double jump, and then lunge. I found this to be a more reliable method since you can judge the distance to the ring and bridge easier. I was able to get the height using this method on every single time trial, so I can assure it is possible. 
 
Use whichever method you're better at though, and don't hesitate to practice a bit until you get it down, since you'll need to do it at the end of just about every time trial.