Hoses & Adapters

Choose your hose by what it connects: regulator hoses run from the first stage to a second stage, BCD & drysuit inflator hoses supply a compatible quick-disconnect inflation valve, and HP gauge hoses connect a pressure gauge. We offer rubber and SCUBAFLEX options, plus adapters for compatible fittings. Open the Tech Tip below for help choosing the type and length.

Hoses & Adapters
Oceanauts Academy: Tech Tip ⚙️ +

Choosing the Right Hose & Length

Choose the connection first, then the length. Both regulator and inflator hoses carry low-pressure gas, so “LP” alone does not identify the hose you need.

1. Hose Types & Connections

  • Regulator hose: First stage to primary, octopus or backup second stage. Typically 3/8″-24 UNF male at the first-stage end and 9/16″-18 UNF female at the second-stage end.
  • BCD & drysuit inflator hose: Typically 3/8″-24 UNF male at the first stage, with an International (Int’l/BCD-style) female quick disconnect at the valve. This also fits compatible SI TECH drysuit valves used on Scuba Force suits, so one hose type can serve either purpose.
  • HP gauge hose: First-stage HP port to pressure gauge (SPG). Typically 7/16″-20 UNF male at the first stage and 7/16″-20 UNF female at the gauge, with the appropriate SPG swivel spool and O-rings.

Male = external thread; female = internal thread. UNF is the thread standard, and the number after the dash is threads per inch. Check your actual fittings: some older first stages use 1/2″-20 UNF LP ports, while CEJN and proprietary inflator couplings differ from the standard BCD fitting. LP and HP hoses are not interchangeable.

2. Dain’s Length Recommendations

Standard Recreational Setup

  • Primary: 75 cm. Regulators commonly arrive with 75 or 80 cm; I prefer 75 cm.
  • Octopus: 100 cm (1 m). The usual length for a conventional recreational alternate.
  • HP gauge: 80 cm. My starting point for a standard recreational setup.

Twinset Setup

  • Primary: 210 cm. A long-hose arrangement, routed and deployed as you have been trained.
  • Backup: 55 cm with a 90° second-stage adapter. This suits my necklaced backup; anything shorter restricts my head turn to the left. Check comfortable movement in both directions.
  • HP gauge: 60 cm, or 65 cm for more reach. 60 cm commonly gives a streamlined route from the left post to the left hip D-ring. Larger divers may find 65 cm more comfortable.

Inflation: My usual choices are 55 cm for a BCD or wing and 90 cm for a drysuit. Our rubber range lists 56 cm rather than 55 cm; other lengths are available on request.

Oceanauts Standard: These are starting points, not fixed rules. Check the fit in your full diving kit: allow comfortable head movement and equipment access without pulling on fittings, sharp bends or large loops. Ask us if you need help matching your hose and routing.