In Rainbow Six Extraction, the very first Study objective of the San Francisco region is notably more difficult than any Study objective you’ll have attempted in New York. The objective, titled Defused, comes under the category Studies in Defusal, and requires you to take down three Breachers or Bloaters. This sounds simple, but a Takedown is a stealth melee kill, and Breachers and Bloaters move around quickly and unpredictably, unlike most of their fellow Chimera. They’re also usually found in packs and tend to explode when you get close to them. These factors make them much harder to sneak up on than other enemies.
It is possible to sneak up on a Breacher or Bloater by crouching and staying behind it. While most Breachers and Bloaters explore and patrol, you’ll sometimes find one that remains relatively still close to a Nest. Wait for any other nearby Chimera to wander off, then patiently sneak up on your target and take it down. Yes, it can be done this way, but it takes a lot of luck and patience. And there are easier ways.
The easiest ways to take down a Breacher or Bloater are to use a Smoke Grenade, Stun Grenade, or if you’re playing as Vigil, the Cloak ability. All of these methods temporarily prevent the target from seeing you, so you don’t have to approach from behind, and it doesn’t matter if the target is already alerted. You might even be able to take down more than one Breacher or Bloater before the effect wears off.
All of these methods still take skill and timing. With both types of grenade, you should throw it from a safe distance and then sprint to reach the target and get your kill before the effect wears off. The Cloak can be activated when pretty close to the target, but you should still try to avoid being seen before and after the Cloak is active.