This is one of the biggest sequence breaks in the game, as Screw Attack is the best overall item in Prime 2.
This lets you go straight from Agon to Sanctuary, which saves several minutes compared to collecting Grapple Beam in Torvus Bog.
These methods also allow you to skip Echo Visor and the Caretaker Drone fight.
Inbounds[]
This is the fastest way to access Screw Attack early. It saves up to 2 minutes compared to the wallcrawl alternative.
The first step is rolljumping through Watch Station Access. If you hit terminal fall farther than the location of the second Grapple point, you will respawn on the other side.
Next, you go to Grand Abyss and do the most notorious trick in the game, the scan dash onto the docked maintenance drone. You only have one opportunity to perform this trick, otherwise you can no longer get to Vault inbounds.
If you made the dash, simply jump onto the second drone and make your way to Vault. If you want to be more careful and not try to make it on the second drone, you can wait for a few seconds and just jump from the first drone all the way to the landing area.
Out of bounds[]
If opting for the wallcrawl alternative, just stay out of bounds after doing Gyro Puzzle Skip and make your way to Watch Station from out of bounds.
Scan dash off of the portal in Watch Station into the aether on the right, and jump on a series of standable spots until you transition to Grand Abyss.
Faster Grand Abyss Wallcrawl
Once in Grand Abyss, jump into the right side of the wall and bomb jump to the top of the room until you're on a standable spot. Once ready, you can simply jump down onto the first drone. Make sure to wait long enough until you do your space jump.
From here, it's easiest to just jump to the second drone and then onto the blue platform. Jumping to the blue platform doesn't lose time since Vault takes a while to load.
While this is nearly 2 minutes slower than the inbounds method, it is still several minutes faster than collecting Grapple Beam.
Backup wallcrawl[]
Although this isn't really applicable in a speedrun, there is a way to still access Vault even if you have missed Grand Abyss and the 2 docked maintenance drones are gone. So, if you aren't particularly concerned with speed and want to get early Screw Attack at all costs, this serves as a last resort method.
Start by doing the SW in Sentinel's Path. It is a bit tricky and you need to be careful with your jumps and manipulating the quad.
Once out of bounds, transition to Watch Station, then immediately go back to the door at the other end (the annihilator door). Make sure the map is still on Watch Station this whole time.
Jump straight off this door and you will finally be ready to aether jump up Watch Station's massive aether box.
Make your way to the skywalk, and use your map to help you determine when you are straight above the door to Grand Abyss. Once lined up, morph and fall straight down.
From here, transition to Grand Abyss and bomb jump around the left side of the room. Around the point where the second docked drone would have been, you should be able to find a standable spot. From here, jump towards the landing area.
Very carefully, wiggle your way down until you hit terminal fall. You want to go as far forwards as you possibly can before falling, to the extent that you are under the middle of the floor. Otherwise, you might not hit the correct terminal fall and be respawned back near Watch Station. If so, you unfortunately will have to repeat the entire process.
Vault[]
Whatever method you used above, there are several ways to collect screw attack without Grapple Beam after entering Vault.
The fastest method is a scan dash onto the platform on the right (or left if you prefer). You can also dash off of the Rezbit.
You can also do a rolljump off of the bridge. This is probably the most difficult method since you need to do a 180 degree turn in the middle of your rolljump, then morph at a specific time so that the camera gets "stuck" on the platform.
Vault Dash Setup
The scan dash method in Vault.
The slowest method is to wait for the Rezbit to get close to the central structure in the room. Then, alert it and shoot it with charged dark beam. Finally, jump on its shield right after it comes up, and from here jump onto the very top of the central structure. You can just jump onto the floating platforms once at the top.
After using all 4 spinners, scan dash or rolljump off the platform so that you fall right under the bridge (while also being somewhat close to the central structure). This should activate the terminal fall that respawns you at the bottom of the central structure. Now, finally, you can use the bomb slot and collect screw attack.
