When encountered in basically unavoidable situations (e.g. Megalodon will almost always find one at the west end of the Death Tunnel, or sometimes in the prey-filled underwater current that runs underneath the "Bog Brush cliffs"), a well-satiated, i.e. not hungry, but fairly healthy shark can survive running into one, but must see to it that it gets access to food quickly after it.
Death mines/Ultra mines seem to have a tendency to pop up the longer one has survived (especially as Megalodon), but there are a few locations where they regularly are (and this only really applies to the Great White or bigger, they are far less frequent if you are the Tiger Shark or weaker)
- Right at the surface in the eastern section of the map between "Toy Robot" and "Teddy Bear" - you can either jump over it or swim by the shallow reef under it, thereby encountering crabs and green jellyfish
- At the western end of the Death Tunnel (if you enter from the east, as many have always done, you'll have encountered some Blob-Fish and Tuna first though, which enables you to run into it without dying)
- At the entrance to the small cave just above the Kempy Cave entryway. It looks dangerous, but it can actually help you find the Kempy entrance quicker without having to look at the map.
- Perhaps not right at the start, but after having survived for a while, they appear in the very western part of the map, close to the entrance to the cave featuring the Electric Guitar.
Appearance in HSW
Ultra mines in HSW are very large, dark, and extremely dangerous. They look like Mega-mines, but with a red line in the middle.
They can one hit kill a XXL shark or smaller.
- It was originally called an Ultra Mine, renamed to Death Mine, and now is once again renamed to Ultra Mine.
- It is referred to both Death Mine and Ultra Mine, for unknown reasons.