Riviera Maya (Quintana Roo) · about 5 km from Tulum
Chan Aktun Ha (Regina Backdoor)
- CertificationFull cave
- Water temperature≈ 24–25 °C (75–77 °F)estimated, no reports yet
- SpecialExperienced divers
Diving and fills
Dive here with
Fills nearby
- Third Dimension DivingEAN32, HP O₂, deco gases and any trimix (booster); Sofnolime 797 and Intersorb; prefilled trimix bailout for rent
- ProTec TulumAir, EAN32, O₂ up to 200 bar, trimix on request (booster); Sofnolime 797 always in stock
- Ko’ox Diving (Tulum)Air, nitrox, O₂ and helium mixes (He about US$2/cf)
What it looks like
Cave Diving In Cenote Chan Aktun Ha (aka Regina's Backdoor) Cave diving @ Cenote Chan Aktun Ha (2019) Chan Aktun Ha - Cave Dive Cave Diving Chan Aktun Ha | Haloclines, Restrictions & Ancient Bones
All 4 videos and posts
Videos and posts
From other divers, via YouTube, Instagram and Facebook. They only load when you click; after that, Google's or Meta's privacy rules apply.
Cave Diving In Cenote Chan Aktun Ha (aka Regina's Backdoor) Cave diving @ Cenote Chan Aktun Ha (2019) Chan Aktun Ha - Cave Dive Cave Diving Chan Aktun Ha | Haloclines, Restrictions & Ancient Bones
Search for more onYouTube ↗Instagram ↗Facebook ↗
Other people's footage, not advice: how someone else dives here says nothing about what suits your team. Dive within your training.
The dive
Chan Aktun Ha (Maya, literally ‘little cave water’) is the back door of the Regina system, hence the nickname Regina Backdoor. Cenote Regina and Shoam themselves are closed to divers, so this is the entrance.
Profile and sections
Chan Aktun Ha (Maya, literally ‘little cave water’) is the back door of the Regina system, hence the nickname Regina Backdoor. Cenote Regina and Shoam themselves are closed to divers, so this is the entrance. From here you can make traverses to Shoam, Regina and, since 2021, to the A tunnel of Mayan Blue.
- Depth and profile
- Unknown
- Configuration
- Unknown; long traverses (DPV/stages are usual)
- DPV: unknown
- Long traverses to Shoam, Regina and Mayan Blue could suit a DPV, but no reports on passages or owner rules found; ask locally
Who can dive where
- At least Full cave
- Configurations: Backmount / twinset / Sidemount / CCR / Small cylinders / no-mount (speleo sumps)
- Configuration unknown — research beforehand
- Experienced divers only
This is how the planner decides who in your team may dive this cave. Rules your own trip adds (organizer, a mail, the AI) show with your trip.
How to get there
Easy access from Hwy 307 south of Tulum; good facilities. Pool without flow, slightly muddy water. Fee unknown.
Around Chan Aktun Ha (Regina Backdoor)
Fills3 fill stations · nearest 4 km
Third Dimension Diving
Calle Chemuyil Mz 14 Lt 01, Mayapax, Tulum
EAN32, HP O₂, deco gases and any trimix (booster); Sofnolime 797 and Intersorb; prefilled trimix bailout for rent
Unknown — call
Rental of backmount, sidemount, CCR cylinders, Suex scooters and stages. In Tulum (Mayapax neighbourhood, west of the 307).
ProTec Tulum
Av. Satélite / Calle Tun-Kul, Tulum
Air, EAN32, O₂ up to 200 bar, trimix on request (booster); Sofnolime 797 always in stock
Daily 8–19
Rental of CCR, scooters, sidemount and double cylinders; CCR room for 14 units. ProTec Playa merged into Tulum in 2026. Keys for Xa'ay Ha (Chi Keen) and Doggi/Style (Muyil) are collected here.
Ko’ox Diving (Tulum)
Tulum
Air, nitrox, O₂ and helium mixes (He about US$2/cf)
Daily 7:30–21:00
Fills CCR, stage and double cylinders; cave gear for rent. Card payment accepted. The site also lists a Puerto Aventuras branch (Hwy 307 km 269.5, 7:30–21:00), but it is not on Google Maps — ask whether it exists and fills.
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News
All (5)
Nearby
Articles about cave diving that name a place within 25 km of this site, but no cave by name. They're not necessarily about this site.
- A Diver Found a Skeleton at Least 8,000 Years Old Hidden 26 Feet Underwater in a Flooded Cave in Mexico ↗
- Cave-divers find trapped spearfisher alive after 15 days ↗
- Cave diving is fraught with danger, but the reward is sights like nothing else on Earth ↗
- INAH files legal complaint for diver damage to underwater archaeological site in Tulum cave ↗
- A Diver Found 8,000-Year-Old Human Remains Deep Inside an Underwater Cave ↗
Access and rules change: check what applies locally right before your trip. Source: GDELT Project and the news feeds of diving magazines. Search for more news ↗ Searched automatically, last on 11 Nov 2026.
More of the latest in Riviera Maya (Quintana Roo, Mexico): conditions, closures and news →Going to the Riviera Maya with your team?
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