Unscrew the nosecone retaining screw
Stand the Quantum VR upright on its flow conveyor so the nosecone faces up. Using the dedicated SUEX wrench, unscrew the central retaining screw on top of the nosecone. Turn anti-clockwise — the screw is not captive, so keep hold of it once it comes free.
Lift the nosecone and expose the ballast bay
Lift the nosecone straight up, taking care not to tug on the battery cables routed through it. With the nosecone removed, the ballast bay is exposed: a brass-coloured threaded seat at the centre with a retaining bracket and two securing screws, and the large separator O-ring sealing the nosecone to the body. Inspect the O-ring for any damage or salt residue before proceeding.
The two ballast cylinders
The SUEX Quantum VR ships with two ballast cylinders: the brass cylinder (left) is the fresh water ballast — hollow and lighter. The lead cylinder (right) is the salt water ballast — denser and heavier, compensating for the greater buoyancy of sea water. The lead cylinder has a threaded pin that seats into the brass ballast holder inside the scooter body.
The installed fresh water ballast
With the nosecone removed, the brass fresh water ballast cylinder is visible seated in the body, held in place by the stainless steel retaining bracket. The bracket spans across the cylinder and is secured by two Torx screws on either side. The bracket must be removed before the cylinder can be lifted out.
Retaining bracket close-up
A closer look at the retaining bracket with the brass fresh water cylinder in place. The bracket fits over the top of the ballast cylinder and is held down by two screws that thread into the scooter body. Loosen both screws fully before attempting to lift the bracket — the cylinder will not clear the bracket until both screws are removed.
Remove the retaining bracket and extract the fresh ballast
With both retaining screws removed, lift the stainless steel bracket clear of the brass cylinder, then lift the fresh water ballast straight out of its seat. The ballast seat — a brass threaded insert in the body — remains in place. Keep the removed bracket, screws, and fresh water cylinder together so nothing is misplaced.
Tighten the nosecone retaining bolt
With the salt water ballast cylinder seated and the retaining bracket screwed back down, lower the nosecone into position and tighten the central retaining bolt using the dedicated tab tool supplied with the scooter. The tab slots over the bolt head and gives enough leverage to tighten it firmly by hand — do not over-torque.
Unscrew the weight disc bolt
Using an allen key, unscrew the central bolt holding the external weight disc stack on the handle bracket. The bolt threads into the bracket body and releases the cap and disc stack beneath it.
Remove the disc stack and add 2 extra discs per side
With the bolt out, lift off the cap and disc stack. For salt water, 2 extra discs are added per side — going from 2 to 4 discs per side (4 to 8 total). Repeat on the other side of the handle. Always keep both sides identical: an uneven count will cause the scooter to roll during a dive.
Reassembled — 4 discs per side, 8 total
The disc stack reassembled with 4 discs per side and the bolt tightened back down. The stacked discs are clearly visible above and below the bracket. Combined with the internal lead ballast cylinder, the Quantum VR is now correctly configured for salt water diving.