A cave diver at the exit of an underwater cave

Photo by Mikhail Vedyokhin · CC BY-SA 2.5

CaveNSS-CDS

Single Tank Cavern Diver

Official course standards ↗Last updated September 7, 2026

Single-tank cavern diving certification for daylight zone overhead environments, providing cavern skills without deep cave penetration or doubles/sidemount equipment requirements. This lightweight entry into overhead diving uses standard recreational single-tank configuration, maintaining sight of the cave entrance throughout all dives. Ideal for recreational open-water divers who want to explore caverns safely but are not ready for full technical training.

What it costs

No centre in the directory publishes a price for this exact certification yet. What follows is what the same training costs elsewhere.

Same training under a different agency

32 centres

A separate set of centres, teaching Cavern under a different agency. These are not the same certification — the standards and the card differ — but they cover the same depth and scope, which is why centres price them alike. Every row here names whose rating it is, and none of them is counted above.

$600 – $1,320across 5 centres pricing in US Dollar

Charged by the day or dive rather than as a course price:

  • Elite Divers InternationalMexico
    Cavern DiverIANTD
    $275/day→ $825 for the 3-day minimum
    $275
    per day
  • Protec MexicoMexico
    CavernPSAI
    1 student$420/day→ $2,100 for the 5-day minimum
    2+ students$370/day→ $1,850 for the 5-day minimum each
    $420
    per day
  • Third Dimension DivingMexico
    Cavern DiverIANTD
    $295/day→ $885 for the 3-day minimum
    $295
    per day
  • Cave AdventurersUnited States
    CavernTDI
    Private class$450/day→ $900 for the 2-day minimum
    Group class$350/day→ $700 for the 2-day minimum each
    $450
    per day
  • Ghost DiversMexico
    Cavern DiverIANTD
    $330/day
    $330
    per day
  • Wolff DivingMexico
    IANTD Cavern DiverIANTD
    $300/day→ $1,200 for the 4-day minimum
    $300
    per day
  • ByMoMoDiveMexico
    Cavern DiverIANTD
    1 student$245/day→ $980 for the 4-day minimum
    3 students$205/day→ $820 for the 4-day minimum each
    $245
    per day
  • Divers UnderGroundMexico
    TDI Cavern DiverTDI
    1 diver$325/day
    2 or 3 divers$300/day
    $325
    per day
  • CDT Mexico (Cave Diving Training)Mexico
    CavernTDI
    1 student$300/day→ $1,200 for the 4-day minimum
    $300
    per day
  • Under The JungleMexico
    Cavern Diver (TDI)TDI
    private$345/day→ $1,725 for the 5-day minimum
    per diver in a group$295/day→ $1,475 for the 5-day minimum each
    $345
    per day
  • Go Dive MexicoMexico
    Cavern diverTDI
    private$330/day→ $1,650 for the 5-day minimum
    2+ divers$300/day→ $1,500 for the 5-day minimum each
    $330
    per day
  • Cave Diving AdventuresMexico
    CavernTDI
    $350/day→ $1,400 for the 4-day minimum
    $350
    per day
  • Green Divers TulumMexico
    TDI Cavern DiverTDI
    per person$235/day
    $235
    per day
THB 20,000 – THB 35,000across 9 centres pricing in Thai Bahtfrom ≈ $597
€800 – €1,000across 3 centres pricing in Eurofrom ≈ $897

Charged by the day or dive rather than as a course price:

Priced per day or per dive in Indonesian Rupiah — see below.

    Charged by the day or dive rather than as a course price:

    • Air Dive AlorIndonesia
      CavernTDI
      1 student, privateIDR 3,200,000/day→ IDR 6,400,000 for the 2-day minimum
      3 studentsIDR 2,400,000/day→ IDR 4,800,000 for the 2-day minimum each
      IDR 3,200,000
      per day
    One centre publishes a price in Mexican Peso.

    Same tier, agency not stated

    5 centres

    These centres publish a price for Cavern, but their own wording does not say which agency's certification it buys — many teach several and name the card only once you enquire, and some price one course for either agency. The figure is comparable; the certification is not identified, so we do not guess at one.

    $500 – $600across 2 centres pricing in US Dollar
    €450 – €800across 2 centres pricing in Eurofrom ≈ $505
    One centre publishes a price in Thai Baht.

    These prices are not like-for-like. Two centres can charge very differently for the same certification because they include different things. One price may cover twinsets, stages, deco gas and cylinder rental for every training dive, a dedicated classroom for the theory, boat or transport to the site, and the agency's registration and materials; another may be tuition only, with all of that charged separately — or the other way round, with a centre bundling in extras the first leaves out. Class size, whether the course is one-to-one, and how many days are allowed for it move the figure too. Check what each centre's price includes before comparing them, and confirm with the centre before booking.

    Consumables are usually extra. Sorb, helium, O₂ and other fills, park and cenote fees, certification fees and rental are commonly charged on top.

    Packages combining several certifications, upgrades from an existing one, and open-ended day rates are excluded — none of them is the standalone price of this course, and including them would move the figures away from what a new student can actually book.

    Prerequisites

    Open Water Diver certification, minimum 25 logged dives. Minimum 18 years old. Basic cavern awareness helpful but not required.

    Standards

    What a diver must demonstrate to pass this course — not always published by the certifying agency.

    Demonstrate proficiency in cavern-specific skills including proper buoyancy and trim, efficient propulsion techniques, effective guideline use and reel management, proper hand signals and team communication, emergency procedures (light failure, loss of visibility, gas sharing), team sequence maintenance, and environmental conservation practices. All diving remains within daylight zone and sight of cave entrance with maximum 30 m/100 ft depth and 60 m/200 ft penetration distance. Minimum 90 minutes bottom time across 4 dives over 2 days.

    Instructors Teaching This Course

    Dive Centres Offering This Course

    We're still building out the directory country by country, so this list isn't every instructor or dive centre teaching it in the world — more locations are coming soon.

    Common questions about NSS-CDS Single Tank Cavern Diver

    What are the prerequisites for NSS-CDS Single Tank Cavern Diver?

    NSS-CDS's standards require: Open Water Diver certification, minimum 25 logged dives. Minimum 18 years old. Basic cavern awareness helpful but not required.

    What is the minimum age for NSS-CDS Single Tank Cavern Diver?

    NSS-CDS's standards state: Minimum 18 years old.

    How many dives do I need before starting NSS-CDS Single Tank Cavern Diver?

    NSS-CDS's standards state: Minimum 25 logged dives.

    How deep can you dive with NSS-CDS Single Tank Cavern Diver?

    NSS-CDS's standards for NSS-CDS Single Tank Cavern Diver set a maximum depth of 30 m.

    What does NSS-CDS Single Tank Cavern Diver training involve?

    According to NSS-CDS's published standards: Demonstrate proficiency in cavern-specific skills including proper buoyancy and trim, efficient propulsion techniques, effective guideline use and reel management, proper hand signals and team communication, emergency procedures (light failure, loss of visibility, gas sharing), team sequence maintenance, and environmental conservation practices. All diving remains within daylight zone and sight of cave entrance with maximum 30 m/100 ft depth and 60 m/200 ft penetration distance. Minimum 90 minutes bottom time across 4 dives over 2 days.

    What is the equivalent of NSS-CDS Single Tank Cavern Diver in other agencies?

    At the same tier in TecDiveTools' cross-agency comparison: TDI Cavern, ANDI Cavern, RAID Cavern, PSAI Cavern Diver, IANTD Cavern Diver and SSI XR Extended Range Cavern Diving. They cover comparable training, but each agency sets its own standards, depth limits and certification card, so they are comparable rather than interchangeable — check which one your next course accepts.

    TDI CavernANDI CavernRAID CavernPSAI Cavern DiverIANTD Cavern DiverSSI XR Extended Range Cavern Diving

    What course comes after NSS-CDS Single Tank Cavern Diver?

    The next step in NSS-CDS's progression is NSS-CDS Apprentice Cave Diver.

    NSS-CDS Apprentice Cave Diver

    Where can I take NSS-CDS Single Tank Cavern Diver?

    2 dive centres and 4 instructors in the TecDiveTools directory teach NSS-CDS Single Tank Cavern Diver, in Mexico and the United States. Each is listed further up this page.

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