GUE vs UTD vs Hogarthian: How the DIR Family Tree Differs

Disclosure: Gardner Underwater teaches through UTD, and Jay Gardner was an owner of UTD until 2026. We've tried to describe both agencies fairly and link to their own descriptions so you can check.

The terms get used interchangeably online, which causes a lot of confusion. Here's how they fit together.

The short version

What is the Hogarthian configuration?

The Hogarthian configuration is a minimalist way of setting up scuba gear: backplate and wing, a continuous-webbing harness, a long-hose primary regulator, a backup on a necklace and as few extra items as possible. It's named for William Hogarth Main, whose work in cave diving shaped it (Wikipedia).

Hogarthian is only about equipment. Many agencies' technical programs teach Hogarthian-style rigs without teaching the wider DIR system. For the pieces and the reasons behind them, see DIR Gear Configuration, Piece by Piece.

What is DIR?

DIR, "Doing It Right," takes the Hogarthian configuration and builds a complete system around it: fundamental skills, team diving, standardized gases and procedures, gas planning and fitness. It came out of the Woodville Karst Plain Project in Florida in the mid-1990s and was formalized by George Irvine and Jarrod Jablonski. We explain it fully in What Is DIR Diving?

DIR itself isn't an agency and doesn't issue certifications. Agencies do.

What is GUE?

Global Underwater Explorers is a training agency built on the DIR system. Its gateway course is GUE Fundamentals. According to GUE:

• Fundamentals normally runs four days, with at least six dives and at least 30 hours of instruction.
• It can also be split into a two-day Part 1 and a three-day Part 2.
• It covers configuration, trim, buoyancy, propulsion including the backward kick, valve management, gas sharing, SMB deployment and nitrox.
• Divers earn a recreational or technical pass. A technical pass supports progression to GUE's technical and cave courses, such as Technical Diver Level 1 and Cave Diver Level 1.
• Fundamentals is a prerequisite for almost every other GUE course.

What is UTD?

Unified Team Diving is a training agency that grew from the same Hogarthian and DIR roots. In 2008 it set a new direction: unifying backmount, sidemount and rebreather diving into one consistent, scalable and interchangeable system (UTD).

UTD describes itself as an inclusive philosophy, and its ideal is a "thinking diver" rather than a "protocol diver": someone who understands why each practice exists, not just how to perform it. UTD allows backmount or sidemount and single or double cylinders where appropriate, subject to the individual course standards. That does not mean single cylinders are suitable for every technical course. At Gardner Underwater, the UTD path for certified divers looks like this:

1. Essentials of Recreational Diving: the entry point into the UTD system for certified divers, normally over three days with video debriefs.
2. Essentials of Tech: a no-decompression personal skills class that prepares you for technical diving.
3. Techreational and Tech 1: decompression diving with trimix, to 130 feet and then 160 feet.

How do GUE and UTD differ?

They share far more than they don't: the same core configuration, a team focus, gas planning, standardized procedures and an emphasis on fundamental skills. The differences are mostly about scope and structure.

• Sidemount and rebreathers. UTD explicitly builds sidemount and rebreather diving into the same system as backmount, so procedures carry across. Check GUE's current catalog for how it handles these.
• Entry structure. GUE starts with Fundamentals and its recreational or technical pass. UTD offers separate recreational and technical essentials courses.
• Course names and progressions. Each agency has its own sequence and standards, which change over time. Always check the agency's current course pages.

Which should you choose?

The instructor matters more than the logo. Look for these things before you look at the agency:

• Do they dive the way they teach? Ask to see video of their own diving.
• Do they explain the why? Good instructors welcome questions about the reasons behind each practice.
• Is the training near where you'll dive? Logistics decide a lot. A great instructor you can train with regularly beats a famous one you see once.
• Where do you want to go? If sidemount or rebreathers are in your future, ask how each agency's system handles them.
• Will they tell you when you're not ready? Honest feedback is the most valuable thing you're paying for.

Strong fundamentals provide a useful starting point when changing training systems. Course equivalency, equipment and procedures still need instructor assessment; a certification from one agency does not automatically meet every requirement of the other.