BP/W 101
As of late summer 2015, I’m currently transitioning from a jacket-style BC to a backplate and wing (BP/W) system. This guide is meant to put all of the 101-level information that I’ve learned into one spot, so that it can be a resource for other divers considering making the change.
NB1: My goal here is to focus on equipment, not diving philosophy – but there are certainly areas of overlap.
NB2: I am not a dive gear expert and I welcome corrections and addenda.
What is a backplate and wing (BP/W) system?
A backplate and wing (BP/W) system is a type of BC. The system is minimalist in nature, and all of the parts are modular. There are two major benefits:
What are the advantages of a BP/W system?
What are the main parts of a BP/W system?
The main parts are the backplate, the wing (air cell, bladder), and the harness. Together, they form a complete buoyancy compensator system.
What is a backplate?
A backplate is a durable, shaped plate that a diver wears on their back. Most plates have a deep groove over the spine, which creates attachment points for other parts of the system.
Backplates are most commonly made out of steel, aluminum, and plastic. Fabric backplates also exist. The price of a backplate varies based on the material, size, machining quality, and other features.
Steel backplates are relatively heavy, aluminum plates are light, and plastic is very light. Cold water divers often like the extra weight from a heavy steel plate; vacation divers appreciate lighter aluminum plates in their suitcases. Choosing the right plate for your dive is part of your weighting strategy.
The shapes and sizes of holes and slot in the backplate are not standardized among manufacturers - some backplates and wings are not compatible because their attachment points are in different places. Remember to check for compatibility before making a purchase.
What is a wing?
A wing is the air cell (bladder) that controls buoyancy. In a jacket-style BC, this part of the system is hidden inside the jacket. In a BP/W system, the wing is attached to the backplate and visible at all times.
Wings come in many sizes, measured by their lift capacity. Lift measures how much weight the wing can hold before it sinks. A single-tank wing may be as small as 22 pounds. A wing meant for doubles tanks may be 55 pounds or larger. Divers choose the best size of wing for their dive by calculating their buoyancy and how much lift they will need.
The price of a wing varies greatly by size, construction, quality, and other features. The shapes and sizes of holes and slots in the wing is also not standard - some wings and backplates will not be compatible. Remember to check for compatibility before making a purchase.
What is a harness?
A harness is a set of straps that secure the diver in their system. There are many different options for harnesses, depending on a diver’s needs and preferences.
The most basic harness option is “continuous webbing.” This is a long piece of tough, flexible nylon webbing (similar to a seatbelt). The webbing weaves in and out of the plate to make shoulder straps and a waist belt.
Attaching a crotch strap from the plate to the belt creates a very secure fit. This configuration is very popular with technical divers.
Some manufacturers sell deluxe harnesses with plastic quick-release buckles, extra D-rings, padded straps, and more.
How does a single tank attach to the system?
The attachment works the same way as a jacket-style BC. A Velcro strap with a metal or plastic buckle is threaded through the BC and wraps around the tank. Almost all backplates have slots for two tank straps. Many divers prefer to have two straps because it makes the tank feel more secure and stable during a dive.
Some divers will also add a piece of equipment called a single tank adapter. The abbreviation for this is STA and it is often pronounced, “stay.” The STA is a metal cradle that attaches to the backplate. The tank is placed into the middle of the cradle, which can help prevent it from rocking back and forth during a dive.
How do a double tanks attach to the system?
Double tanks are attached by doubles tank bands, which connect the two tanks. In between the two tanks is a flat segment, through which a screw secures the tank assembly to the backplate. Double tanks are typically used by advanced divers and technical divers.
Does a BP/W have weight pockets?
Not by default, but there are many different options. To carry weights, some divers will use a weight belt. Other divers will add pockets (either slip-on on Velcro) to their harness, which allows them to place weight where needed. Weight can also go into trim pouches on the tank strap.
Some BP/W manufacturers sell “V-weights” – long, thin weights that fit inside the spine of a backplate – to keep weight evenly distributed in a central location.
The BP/W system may be several pounds negatively buoyant, which may allow a diver to drop the corresponding amount of lead weights. Many divers find BP/W systems more comfortable because this extra weight is distributed across their entire back.
Does the BP/W have gear pockets?
Not by default, because the BP/W starts as a minimalist system. Adding pockets is a personal decision based on diving philosophy. Some divers choose pockets for convenience in carrying extra gear, but technical divers may reject pockets because they believe no unnecessary gear should come on a dive.
A BP/W harness usually has multiple D-rings for clipping on gear. Other options include harnesses for thigh pockets, neoprene shorts with pockets, or using pockets on a dry-suit.
How does a diver get a BP/W?
(1) Many dive shops and online retailers sell BP/W system packages. These typically include the backplate, harness, and all of the necessary hardware to put them together. Deluxe packages may also include a wing and extra hardware (D-rings, slide keepers, etc.) A high-quality package from a reputable dealer can be a great option to hit the ground running with everything you need.
(2) If you have very clear preferences and good gear knowledge, you can build your own package. On a personal note, I would not recommend this option to someone who is not mechanically inclined or unfamiliar with the variety of gear options available.
Who can help with set-up?
If the BP/W was purchased at a dive shop or dealer, a member of the staff should have the training to set it up. The shop may charge a fee for this service.
If you purchased the system online, the seller may have an option to set it up before it ships. The merchant may charge a nominal fee for this service.
If you know another diver who uses a BP/W system, they may have the experience to help you configure your system.
If you will be setting up the system on your own, there are a number of online guides available. Agencies that practice DIR diving require BP/W systems, and provide a lot of information about their mandatory set-up.
What should I expect when I start using the BP/W?
Finding the correct configuration and weighting may take several dives. Adjustments made on the surface are only approximate – the system will act differently underwater. Over time, your small adjustments in harness configuration and weighting will close the gap to perfection.
As of late summer 2015, I’m currently transitioning from a jacket-style BC to a backplate and wing (BP/W) system. This guide is meant to put all of the 101-level information that I’ve learned into one spot, so that it can be a resource for other divers considering making the change.
NB1: My goal here is to focus on equipment, not diving philosophy – but there are certainly areas of overlap.
NB2: I am not a dive gear expert and I welcome corrections and addenda.
What is a backplate and wing (BP/W) system?
A backplate and wing (BP/W) system is a type of BC. The system is minimalist in nature, and all of the parts are modular. There are two major benefits:
- A BP/W system can be adjusted infinitely, so it fits all bodies in all exposure gear
- Divers can add or subtract ANY piece of gear so that the system meets their exact needs
What are the advantages of a BP/W system?
- The system is designed to carry the tank very close to the diver's body, which can help stabilize the tank and reduce the effort of swimming and balancing
- There are many options for distributing weight across the entire system, which supports better trim and balance in the water
- The harness system starts as a simple, clean front with few places to tangle, snag, or create drag in the water
- Divers can add or subtract ANY piece of gear so that the system meets their exact needs
What are the main parts of a BP/W system?
The main parts are the backplate, the wing (air cell, bladder), and the harness. Together, they form a complete buoyancy compensator system.
What is a backplate?
A backplate is a durable, shaped plate that a diver wears on their back. Most plates have a deep groove over the spine, which creates attachment points for other parts of the system.
Backplates are most commonly made out of steel, aluminum, and plastic. Fabric backplates also exist. The price of a backplate varies based on the material, size, machining quality, and other features.
Steel backplates are relatively heavy, aluminum plates are light, and plastic is very light. Cold water divers often like the extra weight from a heavy steel plate; vacation divers appreciate lighter aluminum plates in their suitcases. Choosing the right plate for your dive is part of your weighting strategy.
The shapes and sizes of holes and slot in the backplate are not standardized among manufacturers - some backplates and wings are not compatible because their attachment points are in different places. Remember to check for compatibility before making a purchase.
What is a wing?
A wing is the air cell (bladder) that controls buoyancy. In a jacket-style BC, this part of the system is hidden inside the jacket. In a BP/W system, the wing is attached to the backplate and visible at all times.
Wings come in many sizes, measured by their lift capacity. Lift measures how much weight the wing can hold before it sinks. A single-tank wing may be as small as 22 pounds. A wing meant for doubles tanks may be 55 pounds or larger. Divers choose the best size of wing for their dive by calculating their buoyancy and how much lift they will need.
The price of a wing varies greatly by size, construction, quality, and other features. The shapes and sizes of holes and slots in the wing is also not standard - some wings and backplates will not be compatible. Remember to check for compatibility before making a purchase.
What is a harness?
A harness is a set of straps that secure the diver in their system. There are many different options for harnesses, depending on a diver’s needs and preferences.
The most basic harness option is “continuous webbing.” This is a long piece of tough, flexible nylon webbing (similar to a seatbelt). The webbing weaves in and out of the plate to make shoulder straps and a waist belt.
Attaching a crotch strap from the plate to the belt creates a very secure fit. This configuration is very popular with technical divers.
Some manufacturers sell deluxe harnesses with plastic quick-release buckles, extra D-rings, padded straps, and more.
How does a single tank attach to the system?
The attachment works the same way as a jacket-style BC. A Velcro strap with a metal or plastic buckle is threaded through the BC and wraps around the tank. Almost all backplates have slots for two tank straps. Many divers prefer to have two straps because it makes the tank feel more secure and stable during a dive.
Some divers will also add a piece of equipment called a single tank adapter. The abbreviation for this is STA and it is often pronounced, “stay.” The STA is a metal cradle that attaches to the backplate. The tank is placed into the middle of the cradle, which can help prevent it from rocking back and forth during a dive.
How do a double tanks attach to the system?
Double tanks are attached by doubles tank bands, which connect the two tanks. In between the two tanks is a flat segment, through which a screw secures the tank assembly to the backplate. Double tanks are typically used by advanced divers and technical divers.
Does a BP/W have weight pockets?
Not by default, but there are many different options. To carry weights, some divers will use a weight belt. Other divers will add pockets (either slip-on on Velcro) to their harness, which allows them to place weight where needed. Weight can also go into trim pouches on the tank strap.
Some BP/W manufacturers sell “V-weights” – long, thin weights that fit inside the spine of a backplate – to keep weight evenly distributed in a central location.
The BP/W system may be several pounds negatively buoyant, which may allow a diver to drop the corresponding amount of lead weights. Many divers find BP/W systems more comfortable because this extra weight is distributed across their entire back.
Does the BP/W have gear pockets?
Not by default, because the BP/W starts as a minimalist system. Adding pockets is a personal decision based on diving philosophy. Some divers choose pockets for convenience in carrying extra gear, but technical divers may reject pockets because they believe no unnecessary gear should come on a dive.
A BP/W harness usually has multiple D-rings for clipping on gear. Other options include harnesses for thigh pockets, neoprene shorts with pockets, or using pockets on a dry-suit.
How does a diver get a BP/W?
(1) Many dive shops and online retailers sell BP/W system packages. These typically include the backplate, harness, and all of the necessary hardware to put them together. Deluxe packages may also include a wing and extra hardware (D-rings, slide keepers, etc.) A high-quality package from a reputable dealer can be a great option to hit the ground running with everything you need.
(2) If you have very clear preferences and good gear knowledge, you can build your own package. On a personal note, I would not recommend this option to someone who is not mechanically inclined or unfamiliar with the variety of gear options available.
Who can help with set-up?
If the BP/W was purchased at a dive shop or dealer, a member of the staff should have the training to set it up. The shop may charge a fee for this service.
If you purchased the system online, the seller may have an option to set it up before it ships. The merchant may charge a nominal fee for this service.
If you know another diver who uses a BP/W system, they may have the experience to help you configure your system.
If you will be setting up the system on your own, there are a number of online guides available. Agencies that practice DIR diving require BP/W systems, and provide a lot of information about their mandatory set-up.
What should I expect when I start using the BP/W?
Finding the correct configuration and weighting may take several dives. Adjustments made on the surface are only approximate – the system will act differently underwater. Over time, your small adjustments in harness configuration and weighting will close the gap to perfection.
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