Regulator Buying Guide Written by: Bob Collins Created: 10/02/2017 Updated: 02/15/2026

Scuba Regulator Guide

Before investing in a regulator, you should be familiar with its parts. Today's scuba regulators are far beyond what we've had in years past. Knowing the features and capabilities of each part will ensure you get the most for your hard-earned dollars.

The base scuba regulator is made up of a 1st stage and a 2nd stage. Other parts are added to make a complete air delivery system. Its purpose is to reduce the tank's high-pressure air to the ambient pressure around the diver so they can breathe at any depth.

The First Stage

The first stage attaches directly to the scuba tank. It takes high-pressure air (3000 PSI and above) and drops it to a manageable "Intermediate Pressure" for the 2nd stage. First stages connect to tanks via two main connection types:

• DIN: These screw into the tank valve and trap the high-pressure O-ring so it cannot protrude. They are popular in the technical diving community and overseas.
• Yoke: These are most common in recreational diving and are the standard for aluminum 80 tanks favored by dive operations worldwide.

Note: Unless you plan to take up technical diving, select a yoke fitting for maximum compatibility when traveling with your gear.

The Second Stage

The second stage is the part that goes in your mouth. It takes the intermediate pressure from the hose and matches it to the pressure of the surrounding water so you can inhale effortlessly.

1st Stage Features

Balanced vs. Unbalanced

In simple terms, a balanced regulator breathes the same regardless of how much air is left in your tank. An unbalanced regulator will start to breathe more "stiffly" as your tank pressure drops. While a balanced 1st stage costs more, it provides a much more consistent experience throughout the dive.

Piston vs. Diaphragm

This refers to the internal mechanism used to reduce pressure. Both are highly reliable for recreational diving, but they have slight differences:

• Piston Regulators: Simple design with fewer moving parts and a slight performance edge at extreme depths.
• Diaphragm Regulators: Better for cold or "dirty" water (silt/sand) because the internal parts are not directly exposed to the water.

Ports

Ensure your first stage has enough ports for your setup:

• High-Pressure (HP) Ports: Used for pressure gauges or air-integrated computer transmitters.
• Low-Pressure (LP) Ports: Used for your primary second stage, octopus (backup), BCD inflator, and drysuit hoses.

2nd Stage Features

• Adjustable Second Stages: Desirable models feature a knob to adjust "cracking pressure" (inhalation effort) and a lever to adjust airflow once started. This helps prevent "free-flow" in different conditions.
• Pneumatically Balanced Second Stages: These provide a more natural, effortless breathing sensation.

Warranty and Service

Check the service requirements before you buy. Many manufacturers offer limited lifetime warranties as long as you meet specific service intervals. Remember: while parts may be covered by warranty, the consumer typically pays for the technician's labor.

The #1 rule in buying a regulator is how it breathes. The features above can make or break your investment.