Halcyon Dive Systems
BC System Weighting

BC System Weighting

  • Appropriate distribution of a diver’s ballast is a key ingredient to proper trim and efficient buoyancy control. Traditionally, divers have been taught to place all their ballast on the familiar two-inch waist belt. However, this strategy pulls a diver’s legs down, increasing drag and reducing diving comfort. The wide diversity of Halcyon weighting options allows divers to easily partition weight, supporting optimal balance and reducing diver effort. These unique options notably enhance a diver’s in-water balance, enhancing comfort and diving fun.
  • Choice of backplate: Stainless Steel 6 lb. (2.7 kg) or light-weight hard-coat aluminum
  • ACB Weight Pockets: available in a 10-lb. (4.5 kg) system carrying 5-lb. (2.27 kg) per pocket
  • Standard and Convertible Single-tank Mount (STA): up to 6 lb. (2.7 kg)
  • Trim Weight Pockets (pair):up to 5 lb. (2.2 kg) per pocket


Can I balance “non-releasable “and “releasable“ weighting on my Halcyon BC System?

Halcyon diving systems allow convenient distribution of a diver’s weight in a way that supports diving safety and enhanced diving comfort. Divers can easily mix ditchable and non-ditchable ballast to allow easy removal of a portion of a diver’s weight. For example, this weight might be placed in Halcyon’s patented ACB pockets; these weights can be removed during an emergency or as a means to easily egress from the water. 

How do I determine the required lift capacity of my Halcyon buoyancy compensator?

To determine the required lift capacity of your Halcyon buoyancy compensator, it is necessary to cover the basic concepts relating to proper weighting. Proper weighting requires a diver to be able to maintain a safety or deco stop at 10ft/3m with only 500psi (35 BAR) in the tank. If you can’t maintain neutral buoyancy, adjust weight accordingly. Avoid the temptation to over-weight. Over-weighting requires excess lift, while increasing drag and instability. Moreover, this excess weight is problematic in the event that the diver must swim up from depth. The required lift has little to do with the amount of weight divers are wearing, but instead is tied to their variable buoyancy. Divers’ variable buoyancy is determined by the weight of the gas in their tank plus the loss of buoyancy from their wetsuit (or neoprene drysuit) due to compression at depth. Divers wearing a tri-laminate (shell-type) or crushed neoprene drysuit do not experience such compression, making this calculation even easier. The average ¼-inch (approx. 5 mm) wetsuit looses about 9lb. (4 kg) of buoyancy at 100ft (30 m); 80CF of air from a typical Al-80 weighs 6lbs (2.7 kg), so with an Al-80 tank and a ¼-inch (5 mm) wetsuit, the variation in buoyancy from the start of the dive (at depth with a full tank) to the end of the dive (at 10ft/3m with 500psi/35 BAR) will be 15lb. (6.8 kg).Having weighted to be neutral at the end of the dive, the gas equivalent to 15 lb. (6.8 kg) of lift will need to be added to the BC at the start of the dive (at depth) to be neutral. 

Given that most divers would prefer to be more than just neutral at the surface, it is recommended that all divers double their variable buoyancy requirement to determine their minimum lift BC wing. In this case, the required buoyancy would be 30lb. (13.6 kg) of lift.

There are a few other factors that can increase your lift requirements. One is a desire for your BC to float your gear without you in it. It is not necessarily a requirement, but it can be of benefit—particularly for divers who dive out of an inflatable or don their gear in the water. Determine this lift requirement by adding together the lift needed to float the specific tank uses and how much weight is on the system.

As with any change in one’s diving equipment, it is recommended that all divers make a few dives with their buddy, in controlled conditions, to determine how that change will affect the in-water performance, before returning to their normal diving regimen.

Careful wing selection will ensure adequate lift capacity to meet your diving needs, while avoiding excessive amounts of lift capacity—decreasing drag and effort expended and increasing effectiveness.

Can back-mounted wings provide safe buoyancy on the surface of the water?

The question of surface buoyancy is almost exclusively related to the buoyancy of the diving cylinder. This is true regardless of the style of the BC. For example, our experience in testing a wide range of BC designs shows that the conventional “jacket” style of BCs are greatly affected by the buoyancy of the diving cylinder used. These BCs produce a face-down or side-high surface position with a buoyant tank attached. In order to counteract this effect, divers may use a Halcyon trim weight pocket to counteract the positive force of a buoyant cylinder.

Is the Halcyon BC system appropriate for recreational open-water diving?

Halcyon is one of the world’s most established technical diving brands. However, it is a little-known fact that the majority of Halcyon owners are recreational divers. The Halcyon BC is less cluttered and less restrictive than jacket-style BCs while providing a perfectly tailored fit. This system also creates far less drag in the water and is more stable than conventional jacket-style BCs. These factors reduce diving effort while increasing efficiency and diving fun.