How to Make an Air Compressor for Diving

••• diving boat image by Marcin Wasilewski from Fotolia.com

Air compressors are used in scuba diving to allow for an open system of breathing for a diver at certain depths. The advantage to this type of system is that it offers the ability to dive for as long as necessary without coming back to the surface for more air. These systems are easy to construct from materials found at any home improvement or dive store. The use of a compressor for diving requires a dedicated individual to keep their eyes on the system to watch for operating issues. The system should be tested on the boat or dry land prior to ever attempting an actual dive.

Acquire an appropriate air compressor for the project. The tank must have an automatic pressure switch, at least a 1-horsepower engine and a medium-sized air tank. Since most of the air will be pushed directly down to the diver, the tank doesn't need to be overly large. It simply needs some form of storage in case of a sudden loss of pressure from the engine.

Establish a reliable quality power supply. This is the tricky part, as small boats don't always have the power output necessary for running a compressor. Make sure that there is either a dedicated generator for use on the boat to run the pump, or a power inverter to draw power from the boat's engines without causing a burnout.

Connect an air filter and water separator to the compressor. This will help keep the air quality good coming through the compressor while ensuring that no water backs up into the system and causes damage to the system. Some compressors come with built-in air filters, and semirigid flexible plastic tubing works well for water drainage. Use a socket set or adjustable wrench to make the connections.

Use brass, quick-connect couplings for the air tubing. Brass tubing is an easy-to-connect choice in couplings, and it holds up better in a marine environment than galvanized or aluminum fittings. Be sure to occasionally disassemble, rinse with water, and apply a lubricating spray to all couplings to protect corrosion damage.

Bolt the compressor to the boat deck to avoid any movement of the mechanism during operation. This makes the unit less of a danger for other activities on the boat deck, and it also makes it easier to service and clean. Use sturdy, 3-inch steel bolts and a socket set to connect the compressor.

Purchase a diving set that will have a tether line for a compressed air system of at least 40 feet. Most large dive shops or diving supply stores will either have this or be able to special order it. Also purchase any valves and connectors necessary for use with the equipment and compressor. Connect the tether line to the compressor and tighten it completely with a wrench.


  • Keep compressor-based dives at a maximum depth of 30 feet. Diving deeper runs the risk of the compressor not having enough power to supply the necessary air for the greater depth.
  • Never use a compressor for diving without someone left on the boat's deck to monitor proper function and deal with any loss of pressure or other damage.


  • Become a certified diver and achieve as much training as possible prior to your first compressor dive.
  • Disconnect, clean and check all connections and fittings prior to each use. Keep the unit clean and in perfect working order at all times.


  • "Diver Down: Real-World Scuba Accidents and How to Avoid Them"; Michael R. Ange, 2005
  • "Complete Diving Manual"; Jack Jackson; 2005

Photo Credits

  • diving boat image by Marcin Wasilewski from Fotolia.com