How to Choose the Proper Hose Lengths for Sidemount Diving

A common question asked by new sidemount divers is what hose lengths are needed. While at first glance this appears like a simple question there are some things to consider when choosing the correct hose lengths for your new rig. Hose lengths will depend on the types of first stages and second stages you will use with your sidemount rig, how you want to route your hoses, and the type of sidemount diving you plan on doing.

Standard Hose Lengths

Low pressure regulator hoses – 5 ft/ 1.5 m or 7 ft/2 m if you decide to use a long hose, 15 inches/38 cm to 34 inches/86 cm depending on how you plan on routing short hoses.

Low pressure inflator hoses – 12 inches/30 cm to 15 inches/38 cm long. The most common length is 15 inches/38 cm. (Only one needed if you do not dive in a dry suit.)

High pressure hoses – 6 inches/15 cm to 9 inches/23 cm long.

Regulator Hoses

Some regulators are better suited to certain positions and hose routings than others. Diaphragm first stages similar to the HOG or Dive Rite models work well in any position. That said, they do work better in some positions because of the angle of the high pressure ports. Piston first stages similar to Scubapro and Atomic Aquatic models tend to work better in certain positions.

You need to decide whether you want to use a long hose with your set up. If you plan on diving with others and want the option of donating air, a long hose is recommended. If you plan on diving smaller passages in which you and your team members must pass in single file, you should consider a 7 ft/2 m hose as a 5 ft/1.5 m hose will not be long enough to allow single file exits.

The more difficult hose lengths to determine are the short hoses. Lengths depend hose routings and whether you use elbows on your 2nd stage regulators.

Routing options are

directly from the 1st stage to 2nd stage
around the neck

Some second stage regulators also have the option of the hose connection from either side. This will also have an effect on the hose length. If you use rotating or fixed angle swivels, hose length should be shortened.

Hoses that route directly to your mouth will be 15 inch/38 cm to 22 inch/56 cm hoses. Hoses that route around the neck will be 31 inch/79 cm to 34 inch/86 cm hoses.

Low Pressure Inflator Hoses

The low pressure inflator hose lengths are largely dependent on 1st stage regulator type and which port you choose to use for the inflator hose. The most common hose length is 15 inches/38 cm. This length works well with standard 1stirst stages and any low pressure port. If you have 1st stages with low pressure ports located on the end of the regulator, you will be able to use a shorter hose. There are issues with this method, however.

High Pressure Hoses

The most common high pressure hose length is 6 inches/15 cm. This length works well with the SPG positioned in any direction. The 9 inch/23 cm hose allows for the SPG to be pulled back a little farther from your face. The longer hoses have adopted the nickname of Geezer Hoses because it’s the older generation that usually need to hold things a little farther away to read them.

Common Hose Setup Mistakes

Using hoses that are too long
Using hoses that are too short
Ignoring hose routing
Copying another diver’s configuration exactly

Final Thoughts

I’ve tried multiple hose routing options over the past couple of decades. There is no single routing option that works best overall. However, there are options that will create more wear and tear on your dive equipment that result in having to replace hoses sooner. Hose setup is surprisingly involved and is covered in detail across two chapters in Sidemount Diving: The Almost Comprehensive Guide, including multiple configuration examples.

Readers of the article can receive $10 off the book Sidemount Diving when purchasing directly from the website.

Use code HOSE10 during checkout.

How to Choose Sidemount Cylinders
How to Properly Manage Gas in Your Cylinders
Sidemount Cylinder Rigging: What Matters Most
Sidemount Stage Rigging for Cave Diving
How to Rig Top Mounted Stage Cylinders
Common Modifications of the Dive Rite Nomad

For a complete overview of how these elements work together, see The Complete Guide to Sidemount Diving Configuration.