Category Archives: Technical Dive Training

NAUI Intro To Tech with H-valves

The NAUI Intro To Tech course (Introduction to Technical Diving) is a skills and equipment focused course.

The skills that divers learn are invaluable to all diving, not just technical diving, but are necessary for progression into overhead and decompression environments where precision finning and buoyancy control are essential. Divers learn propulsion techniques with efficient finning, how to kick backwards, and turn in place.

Divers also learn the standard streamlined equipment configuration used in technical diving, and the importance of consistency and redundancy. The NAUI Technical Equipment Configuration (NTEC) is built from the ground up so that large equipment and equipment-dependent skill changes are not necessary are the diver progresses through technical diving.

All of the skills learned in NAUI Intro To Tech will serve a diver well in all aspects of diving even if they do not progress to further technical diving.

An H-valve is a special valve connected to a cylinder to allow two independent first-stage regulators to be connected, mimicking the redundancy of a double-cylinder configuration.

Many divers would like to learn the skills from a NAUI Intro to Tech course, but do not want to progress to using a double-cylinder configuration with a necessary drysuit. When using a single-cylinder with a H-valve, the diver can continue to use a wetsuit and learn all of the diving and most of the equipment skills.

NTEC ConfigurationDouble cylinders - steelDouble cylinders - aluminiumSingle cylinder
ValvesManifold doublesManifold doublesH-valve
Exposure suitDrysuit onlyDrysuit or wetsuitDrysuit or wetsuit

Other required equipment in the NTEC configuration for NAUI Intro To Tech is described in this post. Pro Scuba Dive Center has technical gear available to rent.

An assembled NTEC rig with a single cylinder and H-valve.

If you are interested in taking a NAUI Intro To Tech course please contact or Pro Scuba Dive Center.

Technical Gear (NAUI Intro To Tech)



NAUI Technical Equipment Configuration (NTEC)

The minimum equipment requirements for NAUI classes are summarized in the NTEC Guide. These are broad requirements.

Course information is available in this Overview.

Specific equipment requirements for the Intro To Tech class are summarized in this Checklist. The post below provides more information for consideration.

More gear is required for NAUI Technical Decompression Diver. For a quick overview and comparison to NAUI Intro To Tech, see the Technical Gear Chart post.

It is not recommended to purchase diving gear until you have determined your needs in a class. Discuss any diving gear purchases with your instructor. Pro Scuba Dive Center offers technical dive gear for rental as part of a NAUI Tec dive class.

The following gear is available for rent:

  • Double cylinders
  • Backplate, wing and harness
  • Regulators (long hose, short hose, inflator, drysuit hose, gauges and attached swivel snaps)


First Stage Regulators

Required. Two high performance first stages (one for each cylinder in doubles). Scubapro Mk25 are common due to their excellent performance, build in swivel, and 5th low pressure (LP) outlet on the base, making hose routing easy. NTEC requires a DIN valves and regulators (not the more common yoke valves). DIN adapters should not be used because they introduce another failure point and increase the regulator profile.mk25evo-din


Scubapro Mk25 first stage regulator with 5th port.

Second Stage Regulators

Required. Two second stage regulators are also required, the primary high second stage on a 7’ rubber hose (long hose), and the secondary a 22” rubber hose (short hose) with bungee attached. Both regulators should be high performance regulators.
Miflex hoses are not recommended due to buoyancy differences and tangling on the long hose.s600-2013


S600 second stage regulator.



G260 second stage regulator.





A700 second stage.


A bungee necklace to secure the secondary short-hose second stage.



Required. Solid metal (not plastic). Steel is recommended for a single cylinder. For doubles aluminium or steel are fine depending on ballast requirements. Check with your instructor if you are unsure how to weight yourself for doubles. The backplate must accommodate a continuous webbing.

A optional storage pack can be added to store a lift-bag.



An aluminium backplate.




A steel backplate with cover.


Required. NAUI recommends 55 lb lift capacity for doubles, but the smallest possible is best. A smaller 40 lb might be sufficient depending on ballast requirements. Proper sizing will be covered in class. No bungee on the wing. Wing can be horseshoe or doughnut shaped, but doughnut wings have the advantage of being able to easily shift an air bubble from side to side (or to the dump valves) in a slightly head down position. As a rough guide a 40 lb wing might be sufficient for double 80 ft3 or double 100 ft3 cylinders, but a larger 60 lb wing might be required for double 120 ft3 or 130 ft3 cylinders.

Contact your instructor to help appropriately size the wing. It is not recommended to purchase a wing until ballast requirements are known.

The inflator hose should be approximately 22″.


60 lb doughnut wing


60 lb horseshoe wing with illegal bungee.


Thermal protection

Required. A drysuit is required for steel doubles due to the negative buoyancy characteristics of the cylinders. Extended dive times also increase thermal exposure with long dive times. Divers should train in the same exposure suit used in open water. An advantage of trilaminate drysuits vs crushed neoprene drysuits is that they allow for lots of undergarments, and do not perceptibly change volume with depth. Care should be taken to find fins that fit the boots. Additional storage in two thigh pockets are a major advantage.


A trilaminate drysuit with kevlar kneepads and cargo pockets.


LP hoses

The following hose lengths are should be used as a guide for a person of average height, approximately 5′ 10″.

  • 7′ hose for primary second stage regulator (“long hose”). Shorter people might be more comfortable with a 6′ hose.
  • 22” inflator hose for wing inflator
  • 30” drysuit inflator
  • 24″ SPG hose

Pressure gauge

The SPG must be made of metal (not plastic) and attached to a short rubber hose (about 24”). The SPG will be tied with a swivel snap.


Required. Solid stiff fins are recommended to perform technical finning techniques. Fins with a broad side are recommended in order to back-kick. No split fins. Spring heel-straps are highly recommended.


Scubapro Jet fin


Required. A low-volume mask is recommended. A neoprene slap-strap is recommended to make donning and doffing easier. No snorkel is to be attached, but a folding snorkel can be work in a drysuit cargo pocket if desired. A spare mask carried in the drysuit pocket is recommended.


Required. A few double-ended bolt snaps and swivels are required to secure gear. Snaps must be made from marine grade stainless or brass. I recommend marine grade stainless because the springs are typically more corrosion resistant and easier to operate. Double-ender bolt-snaps are usually 3.5″ or 4″ long, I recommend 3.5″. The smallest 3″ swivel snaps can be hard to operate with thick gloves, 3.5″ swivel snaps are common in cold water. The largest 4+” swivel snaps are usually used to secure a stage or decompression cylinder. Butterfly snaps are forbidden due to being able to be accidentally clipped and entangling the diver.

At least two double ender snaps:

  • Finger spool
  • At least one spare
  • Liftbag (not required for Intro To Tech)

At least three swivel snaps:

  • Long hose
  • Pressure Gauge
  • One per light (minimum of one light)


Double ender bolt snap, and 3 sizes of swivel bolt snaps.

butterfly snap

Forbidden butterfly snaps.


Recommended. Wrist mounted on the right. It is preferable able to read seconds (not just minutes). Most Scubapro  computers can do this in gauge mode, or cycling through the alternative display. The solid strap is typically replaced with bungee. A bottom timer and depth gauge can be used in place of a computer. Either a bottom timer and depth gauge, or a computer, is required.


Wrist mounted dive computer.


Required. Wrist mounted on the left. Technical divers will typically remove the strap and secure the compass with bungee through the mount holes to prevent the strap from becoming loose with depth compression on the exposure suit. Console compasses can typically be converted to wrist-mounted with a different housing or adaptor.fs1wrist_compass_left

Wrist mounted compass.


Required. At a minimum each diver will have one 100 ft spool and 3 ft yellow DSMB.

At the NAUI Decompression Diver level and above two surface marker devices are required. At least one much be a reel and lift-bag, the other can be another lift bag, or a spool and delayed surface marker buoy (DSMB). A liftbag is used for redundant buoyancy in case of wing rupture.

Some dive teams will designate a color for inflation device, typically yellow is the “normal” color and orange or red is the “emergency” color.



A reel and liftbag.



A spool and DSMB.



Required. Back-gas cylinders can be steel or aluminium, all deco and stage bottles may be aluminium only. Some doubles divers prefer alumimium cylinders or low-pressure steel cylinders because the additional cylinder volume can assist diver trim, and the reduced weight can relieve strain on the divers body, however a minimum amount of ballast will be needed in cold water diving, and will likely need to be added to aluminium cylinders anyway.


Double steel cylinders with bands and 300 bar manifold.


Required. One light is required. Is is strongly recommended that the primary light is attached to a hard goodman handle, even if it does not have a power cord and canister battery. Two lights or more light are recommended (one primary light and at least one backup light). Even when not diving in an overhead environment, lights are useful as a communication tool.

The primary light should be either attached to a hard goodman handle (preferred), or a long handheld light with a swivel snap secured to the base. Pistol-grip lights are too bulky and not streamlined.

Backup lights (optional) should be a long handheld light with a swivel snap attached to the base.

best-divers-goodman-handleA hard goodman handle.

Canister lights (not required) are used as a primary light for higher intensity light and longer burn times. Canister lights are recommended for longer duration dives and overhead environments.  If available in class techniques will be taught to avoid entanglement with the light cord. A cord length of 35 inches is recommended as a nominal length, but should be comfortable on the diver. The canister light is attached to the right hip and the cord should reach the left hand with the left arm outstretched.

Canister light

A LED canister light with goodman handle.

A narrow beam angle (approx 10 degrees) is recommended to produce a spot beam for communication. This is important in overhead environments.


Handheld light.

A handheld light is appropriate for the NAUI Intro To Tech course. In more advanced diving where a canister light is required a narrow handheld light can be attached to the harness as a backup. The light should have a hole for a lanyard or other attachment that can be used to attach a swivel bolt snap.

Cutting device

Required. At least line line cutting device is required. A cutting is typically worn on the left waistband or inflator hose. A cutting device can be a knife, surgical scissors or a safety knife.


A low profile titanium dive knife with waist pouch.

Portable table

Recommended. Having a strong, collapsible, portable table is useful for gearing up in training or shore diving. Relatively cheap tables are available from hardware stores, such as the Husky X-Workhorse Workbench.

husky x workhorse openhusky x workhorse closed

A foldable dive table.