Tools
Cylinder Database
Look up the physical specs and buoyancy of common scuba cylinders, with metric and imperial sizing, and feed the right cylinder into the rest of Dive Kit.
Last updated 3 juni 2026
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What it is
The Cylinder Database is a built-in reference of common scuba cylinders with their real specifications. Aluminum or steel, low pressure or high pressure, a single AL80 or a set of steel doubles, each cylinder has different weight, gas capacity, and buoyancy. This screen lets you look those up so you can plan your weighting and gas without guessing.
It is read-only reference data. You browse it, and the same cylinder definitions feed the tools that actually do the math.
How to use it
- From the Plan tab, open Cylinder Database.
- Browse the list. Cylinders are grouped under two section headers, Aluminum and Steel, sorted by name, size, and working pressure.
- Type in the search bar to filter by cylinder name, typical use, or brand (for example “sidemount” or “Luxfer”). Search is fuzzy, so small typos still match. You cannot search by size.
- Tap any cylinder to open its detail view with the full spec sheet.
- Close the detail to return to the list.
If nothing matches your search, the screen shows a message with the text you typed and a Clear search button to reset the list.
Every value reads in your chosen unit. The app supports metric and imperial, set in your app settings, so specs display in litres and bar or in cubic feet and PSI.
What each spec means
The detail view shows the full picture for one cylinder:
| Spec | What it means |
|---|---|
| Free gas | How much breathing gas the cylinder holds at working pressure (water volume × working pressure) |
| Water volume | The internal volume of the cylinder, the physical space inside it |
| Working pressure | The rated fill pressure the cylinder is designed for |
| Material | Aluminum or steel |
| Typical weight | The cylinder’s empty weight |
| Buoyancy | How the cylinder floats or sinks at full, at 50 bar, and empty, colour-coded green for positive and red for negative. Each value also shows an up or down arrow and the word Floats or Sinks, so you can read the direction without relying on colour |
| Typical use | What divers commonly use it for |
| Common brands | Manufacturers that make it |
| Notes | Anything else worth knowing |
Metric and imperial naming
Cylinder names differ by region, and the database shows the size you expect for your units. In metric you see the water volume, for example 10.9 L for the AL80. In imperial you see the free gas volume, the convention behind names like AL80, which holds roughly 80 ft³ of gas, not its much smaller internal volume of about 0.38 ft³. So the same cylinder reads as “10.9 L” in metric and ”≈ 80 ft³” in imperial. The detail view lists free gas and water volume as separate stats so both are clear.
How cylinders feed other tools
The cylinder definitions here are shared across the app. When you pick a cylinder in the Gas Usage planner, the Buoyancy Calculator, or the Gas Blender, it draws on this same data for water volume, working pressure, and buoyancy. Browsing the database first helps you choose the right cylinder before you plan with it.
Behaviour and limits
The specs are representative reference values for standard cylinder types. Your actual cylinder may differ slightly in weight or volume depending on the manufacturer, valve, and any extra hardware. Buoyancy figures assume the cylinder alone, without regulator, bands, or rigging, so treat them as the cylinder’s contribution rather than your whole rig.
Related
- Gas Usage uses these cylinder specs to plan how much gas a dive needs.
- Gas Blender uses the cylinder size when working out a fill.
- Buoyancy Calculator pulls cylinder buoyancy into your weighting.
Parts of this guide were drafted with AI assistance and may contain mistakes. It's educational, not a substitute for training. Always dive within your certification and verify with your instruments.