The Gravity Suit is an upgrade that allows Samus to traverse unhindered through water or lava. Normally, the Gravity Suit becomes accessible after obtaining Space Jump, however, using a developer-intended shortcut, it becomes accessible just after obtaining Ice Missile, or instead it can be obtained just after obtaining Plasma Beam, before obtaining Ice Missile.
The glitchless version of Early Gravity Suit after Ice Missile requires some practice but is is fairly straightforward to perform once learned. It involves timing a single shinespark over water, then after that, taking a teleportal and solving a speed keep shinespark puzzle where you need to destroy some beam blocks along the way and follow a couple hidden pathways. Upon reaching the end, you will find yourself at the end of the shortcut above Gravity Suit Room, in the Lower Burenia Gravity Basin, where you will be able to destroy some diffusion blobs and a grapple beam block to bring down the Tower Object and gain access to the Gravity Suit room below.
Early Gravity Suit after Plasma Beam is much more difficult to pull off, even for skilled players. It starts by using a Water Bomb Jump to gain access to the plasma beam door in the Burenia Water Basin, skipping the need for Space Jump. To traverse underwater from here to the Gravity Suit Room, at least one damage boost out of a water bomb jump off a moving enemy is required, and then either another damage boost in the same way or a pseudo beam is required to finally gain access to Lower Burenia Gravity Basin, where you then can access the Gravity Suit Room in the standard way, by destroying the diffusion blobs and grapple beam block and bringing down the Tower Object. This method is difficult because you are given a finite number of opportunities to traverse the path. Failing a jump, receiving too much damage, or even accidentally destroying all the enemies in the room can cause the route to fail, forcing a reset to checkpoint or save.
In non-Vanilla runs of Dread (e.g. rando), the Gravity Suit room can also be accessed by performing an ADC sink through the top of the Lower Burenia Gravity Basin, to the left of the Tower Object, above the room where you access the grapple beam block. Once where, the blobs and grapple beam block for the Tower Object can be destroying, giving access to the Gravity Suit Room.
After defeating the Blue EMMI and getting Ice Missile, go to the Energy Recharge Station below Pulse Radar Room, above where you acquire Spin Boost, and destroy the Enky to your right blocking your path in the hallway.
Run to the end of the hallway on the right, then speed booster back left and charge a shinespark.
Quickly drop through the morph ball tunnel to your left down into the water below, then jump and shinespark across the gap to your right. Make sure you jump high enough to clear the ledge opposite you.
From there, go forward through the morph ball tunnel and drop down through the pitfall blocks, then take the Ghavoran Green Teleportal to Burenia.
From the green portal, destroy the stretch of bomb blocks on the ground to your right, leading to a series of Enky you must destroy.
At the bottom, you'll encounter a door leading to a pickup. On the walkway, charge a speed boost to the left, and if done right, you will break the pair of speed booster blocks leading to a hidden pathway below. If you don't break the blocks, shinespark through them, and charge another speed booster. If you wait to open the door above just before you pass through it, you will have enough time to wallkick off the opposing wall and run back left, keeping your speed booster. Charge a shinespark at the end of the walkway, and drop through the right.
Using your shinespark after breaking through some beam blocks, solve the speed booster puzzle, passing through speed booster blocks at the end to break into the Lower Burenia Gravity Basin where the Gravity Suit Room is.
From here, climb up the terrain to the room overlooking the diffusion blobs connecting to the tower object, destroy the diffuion blobs and then the grapple beam block to cause the tower object to come crashing down. Access to the Gravity Suit Room below, and use a shinespark escape out the way the tower object was blocking before.
From Burenia, drop down into the Burenia Water Basin and grapple left onto the spider magnet block, pulling it down.
Reach the plasma beam door above by performing a Water Bomb Jump. Once through, make your way to the power beam door below.
Once through the power beam door, don't drop down further below. Instead, walk and hang onto the ledge, hold L-aim and aim directly at the middle of the diffusion blob block, and fire a charged shot to damage the diffusion blob once.
After the diffusion blob has taken a hit once, charge another shot and while holding it, drop down off the ledge and hold left, re-spinning if necessary, and shoot your second shot, destroying the diffusion blob as you fall down, holding left to grab the ledge.
Once through the power beam door, jump over the gap and land on the right platform, where the ramming blue fish enemy is.
Destroy the fish enemy, fire two charged diffusion beam shots to destroy the diffusion blob block guarding the pathway to the left across the gap, and then jump slightly out away from the platform using a water bomb jump to gain enough height and distance to clear the gap.
Once through the power beam door, jump over the gap and land on the right platform, where the ramming blue enemy fish is.
Fire two charged diffusion beam shots to destroy the diffusion blob block guarding the pathway to the left across the gap, but do not destroy the enemy fish.
Bait the fish enemy to your right, jumping over it, and then position Samus over the first couple of red lights on the platform you are standing on. Wait for the enemy fish to notice you and prepare to charge at you. You must have full health in order to survive this attack.
As soon as the enemy hits you, hold left and drift across the gap, using the damage boost from the enemy's attack. Once on the other side, destroy the second blue enemy fish there to regain your health back.
After you defeat the second blue fish, store a water bomb jump and then destroy the grapple beam block to your right, directly across the gap.
A swarm of fish will come out of the morph ball tunnel. As they prepare to attack you, jump up and perform your water bomb jump, and if successful, you can gain enough height from the water bomb jump and then damage boost off the fish swarm as it rushes in to attack you. Grab the ledge above and climb up. It's recommended to use the save room at this point.
Drop down past the whale and travel to the right, until eventually you are in a room with a lone blue balloon fish hovering above you.
Jump up to the platform just below the enemy, and this will cause it to go into an attack animation, firing energy bullets in all directions. You need to have it start its attack while slightly left above the corner of the edge. Immediately after it starts its attack, water bomb jump up and left, holding left to damage boost off one the bullets flying past you, grab the ledge above and quickly jump up, dodging more bullets. Make your way up through the two sensor doors and be careful not to die to the powered up X-enemies inside.