null

First & Second Stages

First & Second Stages

Free Shipping across Canada! All orders over $150
Orders Processed and Shipping Fast!

We are Canadian! Orders shipped from our Edmonton warehouse

High Quality Gear -  Divemaster & Instructor tested and approved

Buy individual scuba regulator first stages and second stages in Canada — standalone components for divers building a custom regulator configuration, upgrading an existing setup, or adding a backup regulator to their kit. First stages available in yoke and DIN configurations, balanced piston and balanced diaphragm designs, and environmentally sealed models for cold water diving. Second stages include primary and backup (octopus) options from Scubapro, Cressi, and Scuba Force. Looking for a complete ready-to-dive system? See our regulator packages. .
Tips on choosing the best regulator

What to know about first and second stage regulators

Downstream vs. upstream second stage valves
A downstream valve opens in the same direction as airflow — if the first stage over-pressurizes, the downstream second stage opens automatically, resulting in a free-flow. This is the preferred design for recreational diving because a free-flow is manageable at the surface. An upstream valve opens against the airflow — if the first stage over-pressurizes, the valve can jam closed, cutting off the air supply. Upstream valves are used in specific technical configurations but are not recommended for recreational diving. All primary and backup second stages we carry for recreational use are downstream valve designs.

LP port count — planning your hose configuration
Most first stages have four low pressure ports and one or two high pressure ports. Your low pressure ports need to accommodate your primary second stage, backup second stage, BCD power inflator hose, and drysuit inflator hose if applicable — that's up to four hoses from low pressure ports alone. If you run a drysuit, a sidemount configuration, or a redundant computer transmitter, confirm your chosen first stage has enough ports before purchasing. The Scubapro MK25 EVO adds a fifth low pressure port with swivel, specifically for divers who need additional hose routing flexibility.

Primary vs. backup second stage — the difference matters
A primary second stage is optimized for breathing comfort — adjustable inhalation effort, dive/pre-dive lever, and high-performance airflow. A backup second stage (octopus) is designed for reliability and simplicity — typically non-adjustable, brightly colored (yellow is standard) for easy identification in an emergency, and built on a downstream valve design that defaults to a free-flow rather than a blocked valve if something fails. Backup second stages are mounted on longer hoses — typically 36 inches — so a buddy in distress can take it without pulling you toward them.

DIN conversion and adapter options
If you own a yoke first stage and need to dive on a DIN tank, or vice versa, adapters allow conversion without purchasing a new regulator. The DIN to Yoke Spin-On Adapter fits any DIN first stage and allows connection to a standard yoke/K-valve tank. The Scubapro DIN Conversion Kit converts compatible Scubapro yoke first stages to DIN permanently. If you travel between North America and Europe regularly, carrying a DIN to yoke adapter is simpler than owning two regulators.

Frequently asked questions

Can I mix first and second stage brands?

Generally yes — scuba regulator hoses use standardized thread fittings, so a Scubapro first stage can be connected to a Cressi second stage using a standard hose. However, for warranty purposes, most manufacturers prefer their components to be serviced and used together. Performance matching also matters — pairing a high-performance first stage with a basic backup second stage is common and works well. If you are unsure whether specific components will work together, contact us before ordering.

What does the dive/pre-dive lever on a second stage do?

The dive/pre-dive lever adjusts the cracking pressure of the second stage — in pre-dive position, the regulator requires a slightly harder inhale to open, which reduces the likelihood of free-flowing at the surface when the regulator is out of your mouth and exposed to splashing or wave action. In dive mode, the cracking pressure drops to the minimum for easiest underwater breathing. Always switch to dive mode before putting the regulator in your mouth underwater. Some regulators call this lever by different names — Venturi control, VAD (Venturi Adjustment Dial), or IVA (Inline Valve Adjuster) — but the function is the same.

What is the yellow hose on a backup regulator for?

Yellow is the internationally recognized color for a backup second stage (octopus). In an out-of-air emergency, a dive buddy in distress needs to locate your backup regulator quickly and under stress. The bright yellow hose and second stage make it immediately visible even in reduced visibility conditions. Your backup regulator should be mounted in the triangle formed by your chin, navel, and the sides of your chest — the standard "golden triangle" placement taught in open water certification. We carry yellow octopus hoses in 36-inch length as a replacement or upgrade for any backup regulator setup.

What is the difference between the first stage and second stage scuba regulator?

A scuba regulator has two main parts that work together to deliver breathable air underwater, the first stage and second stage. The first stage attaches directly to your scuba tank valve. Its job is to reduce the high-pressure air from the tank to an intermediate pressure that can be safely delivered through the regulator hoses. The second stage is the part you breathe from. When you inhale, it further reduces the air pressure to match the surrounding water pressure, delivering air comfortably and on demand. In simple terms, the first stage reduces tank pressure, while the second stage delivers air to the diver at a breathable pressure. Both are essential components of a safe and reliable scuba diving regulator system.