Training agency
Technical Diving International
International
5 cave courses
TDI, TDI-SDI, SDI-TDI, TDI/SDI/ERDI
A technical diving training agency founded in 1994, whose overhead programme runs from Cavern Diver through Intro to Cave and Full Cave, with stage, scooter, survey and rebreather cave options.
Technical Diving International (TDI) describes itself as having been founded in 1994, with its sister agencies Scuba Diving International (SDI) following in 1998 and Emergency Response Diving International (ERDI) and Performance Freediving International (PFI) in 2000 [1]. Its own history page gives two different counts for its international offices, so this reference does not quote one.
TDI's cave programme is a staged sequence. Cavern Diver is the entry course and is explicitly not intended to teach cave diving; Intro to Cave Diver is the second level; Full Cave Diver is described by TDI as the third stage of what it calls its Full Cave Diver Development Program [2][3][4]. TDI's course catalogue also lists Stage Cave Diver, DPV Cave Diver, Cave Surveying Diver and rebreather versions of the cavern, intro and full cave courses [5]. The public course pages state prerequisites and post-certification limits; the full standards are referenced separately.
5 courses
Cave-related courses
As published on the organisation's own course or standards pages; the official page is the authority. Similar names elsewhere are not automatically equivalent.
| Course | Prerequisites | Scope and published limits |
|---|---|---|
| TDI Cavern Diver ↗Cavern · min. age 18 · checked 2026-10-14 | Minimum age 18, or 15 with parental consent; SDI Open Water Scuba Diver or equivalent; proof of 25 logged dives. | Entry course for overhead diving in the cavern zone: cavern diving policy, gas management including dissimilar cylinder volumes, equipment and configuration, light and hand signals, trim and buoyancy, line following, stress management, conservation, problem solving (equipment failure, silting), accident analysis and etiquette. Skills include laying and following a guideline with eyes open and closed, air sharing including with lights off, and a simulated primary light failure. TDI states the course is not intended to teach cave diving.As published for certified graduates: penetration by the rule of thirds, or one-sixth when using doubles; maximum depth 40 m; penetration no more than 61 linear metres from the surface; continuous guideline; no restrictions or passages too small for two divers side by side; dives should approximate training. |
| TDI DPV Cave Diver ↗Scooter (DPV) cave · min. age 18 · checked 2026-10-14 | Minimum age 18; TDI Full Cave Diver or equivalent; at least 25 non-training full cave dives. | Use of diver propulsion vehicles (scooters) in caves: equipment and burn time, rigging, failure and towing scenarios, gas sharing, team separation, which passages are and are not suitable for scooters, low-impact riding, and planning with turn time, distance and pressure.As published: with one DPV per diver, turn the dive with no less than twice the gas needed to swim out; with multiple DPVs, no less than twice the gas needed to exit on a DPV; no equipment removal in the cave except stage cylinders; maximum depth 39 m. |
| TDI Full Cave Diver ↗Full cave · min. age 18 · checked 2026-10-14 | Minimum age 18; TDI Introductory Cave Diver or equivalent; TDI Decompression Procedures or equivalent if decompression dives are part of training (may be taken concurrently). | Third stage of TDI's Full Cave Diver Development Program. Adds lost-line and lost-diver drills, use of reels for jumps and gaps, and broader planning and gas management to the intro-level skills.As published: penetration by the rule of thirds; maximum depth 40 m; continuous guideline; dives approximate training; safety and decompression stops as appropriate if decompression-trained. Written exam pass mark 80 percent. |
| TDI Intro to Cave Diver ↗Intro cave · min. age 18 · checked 2026-10-14 | Minimum age 18, or 15 with parental consent; TDI Cavern Diver or equivalent. | Second level of TDI overhead training. Extends cavern topics into the cave: policy, gas management including dissimilar volumes, equipment, communication, swimming technique, physiology, conservation, problem solving and accident analysis. Skills include guideline deployment and line markers, eyes-closed line following, air sharing with and without lights, and exiting on a backup light. Graduates may dive single-guideline caves without direct supervision within the published limits.As published: penetration by the rule of thirds, or one-sixth when using doubles; maximum depth 40 m; continuous guideline; planned dives must not exceed current certification and should approximate training. Written exam pass mark 80 percent. |
| TDI Cave Surveying Diver ↗Survey project · min. age 18 · checked 2026-10-14 | Minimum age 18; TDI Full Cave Diver or equivalent; at least 25 non-training cave dives. | Underwater cave survey: compass use and errors, sketching, survey stations, vertical and radial surveys, large chambers and long passages, data collection and verification, single-line and high-grade maps, plus landowner relations and local access requirements.As published: penetration by the one-third rule or a more conservative plan at the instructor's discretion; maximum depth 39 m; minimum starting visibility 6 m; no equipment removal in the cave. |
14
Providers stating this affiliation
| Provider | Where | How we know |
|---|---|---|
| Blue Water Ascent | Melbourne | Provider's own website |
| Deep Blue Ventures | McCrae, Victoria (Melbourne area) | Provider's own website |
| Dive Experience | Mount Gambier | Provider's own website |
| Diving Adelaide | Marleston (Adelaide) | Provider's own website |
| Cristina Zenato | Grand Bahama | Provider's own website |
| The Cave To Be | Gramat | Provider's own website |
| MJ Cave – Molnár János Cave Dive Center | Frankel Leó u. 48, Budapest | Provider's own website |
| Under the Jungle | Xpu Ha (between Puerto Aventuras and Akumal) | Provider's own website |
| Underworld Tulum | Tulum | Provider's own website |
| Yucatek Divers | Playa del Carmen | Provider's own website |
| Plura Valley | Plurdalsveien 1495, Skonseng (Rana) | Provider's own website |
| Cave Adventurers | Marianna | Provider's own website |
| Cave Country Dive Shop | High Springs | Provider's own website |
| Dive Outpost | Live Oak (near Luraville) | Provider's own website |
Further reading
Cave diver training stages and terminology
Most agencies move divers from cavern to an introductory or limited cave level and then to full cave, before...
Cavern and cave diving: what is the difference
Cavern diving stays in the daylight-lit entrance area of a cave; cave diving goes beyond it. Agencies define the...
How to choose a cave instructor or training provider
Questions to ask before booking cave training: which standard applies, whether the instructor is currently...
Keeping skills current: continuing education, currency and mentoring
Most cave cards never expire, but agencies build currency into their limits and progression rules: dive within...
Reels, Spools, Guidelines and Line Markers: What They Are For
The continuous guideline is the cave diver's route home. This article explains reels and spools, what guidelines are...
Specialist areas: sidemount, rebreathers, scooters, surveying and scientific diving
What cave specialities involve, what agencies require before them, and the limits they publish. Nearly all assume...
Cave Diving Directional and Non-Directional Markers 101 ↗
Clear explanation of line arrows, cookies and referencing exit markers (REMs), the difference between...
Every fact on this page, with its source (4)
| Fact | Status | Source |
|---|---|---|
| TDI says it was founded in 1994.Some secondary sources give 1992 or 1993; the agency's own page says 1994. | Verified | [1] |
| SDI launched in 1998; ERDI and PFI date from 2000, according to TDI. | Verified | [1] |
| TDI's overhead sequence is Cavern Diver, then Intro to Cave Diver, then Full Cave Diver, which TDI calls the third stage of its Full Cave Diver Development Program. | Verified | [2] [3] [4] |
| TDI's catalogue lists Stage Cave Diver, DPV Cave Diver, Cave Surveying Diver and rebreather cavern, intro to cave and full cave courses. | Verified | [5] |
Verified: stated by an official or primary source we opened. Reported: from a secondary source only. Sources conflict: the note gives both versions. May be out of date: the newest source we found is old.
Written in our own words from the sources above. Report a correction