Evo nutrient caches are great resources in Maneater, and each area has a dozen or more of the useful crates hidden somewhere. Hopelessly swimming around is one way to try and find them, but there is an easier way to try and track them down.
As you swim through the game’s areas, you need to spam your radar. The radar sends out a pulse and will briefly highlight the things around you. It can pick up all manner of items, from large tunnels that allow you to get to new areas to markers for landmarks. It will also pick up nutrient caches, which you can eat to gain a large amount of experience, and level up faster.
Nutrient caches will also drop a large number of useful resources, so finding them is very worthwhile. The good news is that, once you find them, they will be automatically marked on your map, and you can return to get them later if you are too busy chasing something down.
The best thing to do is get in the habit of spamming your radar as you swim around, marking up all the items of interest and nutrient caches so you can get then pick them up at your leisure. When you find a cache, you can smash it or bite it open to get at the goodies inside.