Ryan Booker
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  • If There's No Map, Have You Really Been There?

    In the last week of our time in Mexico, I took GUE Underwater Cave Survey with Fred Devos (Zero Gravity), and teammate JY—a mix of classroom work, field drills, and real world work continuing the resurvey of Nai Tucha (Tux Kupaxa).

    A hand drawn cave survey map.

    Spending over 10 hours in the same area opens your eyes to how much is really there, how much you usually miss, and how much you will always find, no matter how many times you’ve been there.

    Like taking Cave 1 and 2, Underwater Cave Survey opened my eyes anew.

    A three quarter shot of a man in a grey t-shirt, cargo pants, and a camouflage hat, standing in the jungle and writing in wetnotes using a pencil with a handheld compass attached to it.Making Notes A close up of two men working on a cave survey map.Drawing a Scale Map A close up of underwater survey notes and a halcyon second stage regulator, on top of a set of twin AL80 scuba tanks, overlooking the crystal clear green hued water of a cenote.Underwater Notes

    📸 Photos: Copyright © 2023, Fred Devos.

    → 9:00 AM, Feb 8
  • Una desviación para los tacos

    After Christmas In Austin we braved Southwest Airlines and headed to Mexico—AUS✈️CUN was one of the few flights largely unaffected by the whole mess. Our last trip was late 2019, immediately before… everything.

    Three corn tortilla soft tacos on a white plate. One with chicken and rice, and two pork pastor with corriander, onion and rice.

    The Yucatán Peninsula is a huge limestone karst formed millions of years ago and shaped by everything from ice age and glacial melt to meteor impact1. It’s jungle landscape marked by thousands of cenotes, doorways into another realm, many of them woven into the life and mythology of the Maya.

    Once dry, the cave systems are full of beautiful speleological decorations, the remains of ancient mega fauna, fire pits and artefacts from another lifetime, and sometimes the people that may have inhabited them.

    We spent two weeks diving and exploring this beautiful world.

    I have far too much video to sort though—I’ll post some short clips in the future—perhaps some photos will help explain the draw.

    The first rule of cave diving is to always have a continuous guideline to the open water2.

    A diver hovering among the rocks leading into an underwater cave system, tying a guideline reel to a nearby fallen tree branch, the crystal clear water casting a green blue hue across the scene.Primary Tie-off Two divers descend into the an underwater cave system, their gruideline tied to a nearby fallen tree branch, the crystal clear water casting a green blue hue on the scene.Heading In A Halycon Pathfinder guideline reel securely tied into the main line of an underwater cave system.Tied Into the Mainline

    Once inside, it’s dark, eery, and beautiful. The lights you have with you the only source of illumination.

    A diver swims down a lava tube in an underwater cave system, his dark drysuit and greyscale camouflage fins lit by a team mates primary light, as it illuminates the walls of the cave in greens and blues.Lava Tube A diver swims through dark speleothems and covered in silt an eery green cast illuminating the scene. Speleothems The silouhette of a diver against the brightly lit cave walls and myriad delicate speleothems outlining an underwater cave tunnel.Delicate Speleothems

    One of the most beautiful sites in caves close to the sea is the halocline, an area where the inland fresh water mixes with salt water from the ocean—beautiful and sometimes frustrating when you’re in the rocking chair.

    A diver swimming through a brightly lit white pock marked cave, their hand dragging through the halocline mixing the fresh and salt water layers, trailing a blurry interface behind them.Mixing the Halocline, from Above A completely blurred view of a brightly lit cave tunnel. The halocline so mixed that visibility has dropped to near zero, like looking through a deeply defocused camera lens.In the Middle of the Halocline A diver swimming through a brightly lit white pock marked cave, through the middle of the halocline mixing the fresh and salt water layers, trailing a blurry interface behind them.Mixing the Halocline, from Below

    As always, I’m counting the days until we head back to the Mayan Underworld.


    1. There is a world of information available online about karst geology and hydrogeology. Here’s a good summary of the Yucatan. ↩︎

    2. See Sheck Exley’s foundational book Basic Cave Diving: A Blueprint for Survival. ↩︎

    → 3:01 PM, Feb 5
  • That’s a good looking team.

    → 8:07 PM, Aug 8
  • I spent the last month or so in Mexico and Florida cave diving.

    One of my team mates, Huw Porter, produced a nice video of some of the highlights, Limestone Rhapsody.

    → 2:01 PM, Nov 15
  • I spent the weekend diving in Tank Cave. I always love these guys.

    → 7:19 PM, Sep 17
  • A couple of snaps of us working at the Battle of Egadi this season.

    → 10:07 PM, Aug 20
  • Interested in diving? Exploration? Adventure? Aged 21–30?

    See where diving can take you, and check out GUE’s NextGen Scholarship

    → 11:04 PM, Jul 18
  • Prepping for another day of exploration… while I pack up ready to head home for the season.

    → 6:47 PM, Jul 13
  • Out of the deep. Lingyu He and I decompressing after some exploration.

    → 2:00 AM, Jul 9
  • Heading to 80m to investigate a Roman ram from 241 BC.

    → 3:15 AM, Jul 5
  • The conditions are just terrible.

    → 6:04 PM, Jul 4
  • We had a great dive this morning. Down to 80m to check an ancient ram that’s been sitting on the sea floor since the battle on 10 March 241 BC.

    → 1:08 AM, Jul 2
  • Home for the next couple of weeks.

    IMG 0337IMG 0969IMG 9164

    → 2:29 AM, Jun 30
  • Today we say ciao Lipari, and head to Favignana.

    → 4:24 PM, Jun 28
  • We had our final dive in Capistello Bay this morning, finishing some survey measurements. Now we’re all packed for Favignana tomorrow.

    → 1:48 AM, Jun 28
  • Beautiful weather and calm seas for a few dives surveying the Capistello Bay wreck. We cleaned up some points and added a couple of ancient Roman anchors to the survey.

    → 4:17 AM, Jun 27
  • Back to Fundamentals: An Introduction to GUE’s Most Popular Diving Course

    → 8:17 PM, Mar 22
  • A quick update from GUE president Jarrod Jablonski, including a great chat with Richard Lundgren regarding our new CCR1 and CCR2 programs.

    → 2:20 AM, Dec 20
  • Recently, GUE released a great new blog for all things diving. Check it out!

    A good place to start is a 20 year retrospective from GUE king pin Jarrod Jablonski.

    → 4:28 PM, Dec 11
  • Help celebrate GUE’s 20th anniversary, with this special edition backplate and wing.

    → 7:36 PM, Sep 11
  • Happy 20th Anniversary! Some updates from Global Underwater Explorers.

    → 4:22 PM, Aug 12
  • In 2016, I joined the Lipari Acheo Project for Global Underwater Explorers and the Soprintendenza del Mare of Sicily, cataloguing and mapping the “Capistello Bay” wreck, a greek cargo ship from around 300 BC.

    An amazing experience. I’m excited to rejoin the project this week.

    → 2:04 PM, Jun 19
  • The Thresher Shark Research And Conservation Project, Quest Magazine

    An article I wrote (with fellow GUE diver Nathalie Udo) about our experience with TSRCP in the Philippines has finally been published in the latest issue (12.3) of GUE’s Quest Magazine (available with GUE membership).

    → 8:28 AM, Oct 30
  • The Thresher Shark Research & Conservation Project

    In 2011 I’ll be returning to The Thresher Shark Research & Conservation Project for a six month stint as Science Officer. Helping out on an important scientific and community project with some of the greatest people I’ve had the pleasure to meet and work with.

    I spent the best three months of my life there in 2009. Diving every day, researching sharks and mantas, and helping a small island community—through the research and its application to conservation and within the local dive tourism industry, but also directly within the community, where the project provides jobs, helped construct housing and where TSRCP volunteers teach marine biology and conservation at the local school.

    Life on the island was confronting at first. About 2 km square consisting of a couple of small villages and a few dive resorts (largely foreign owned, but where the island community gets 80% of its income), there is no permanent electricity and no fresh water. The island is powered by petrol generators prone to breakdown and drinking water is imported daily. A simple, largely subsistence lifestyle. I grew to love the island and its people.

    History

    TSRCP was started in 2005 by research scientists Simon P. Oliver and Alison J. Beckett to create a baseline of Monad Shoal in the Philippines—primarily concerned with Pelagic Thresher Shark (Alopias pelagicus) cleaning activity as well as the shoal’s coral coverage and general health.

    Monad Shoal is about 8 km east of the southern beach of Malapascua Island in the Visayan Sea—an open water seamount with a relatively square dive profile around 21–24m that plunges to 250m, presenting a unique opportunity to observe and record these rarely studied oceanic sharks.

    Both threshers and Manta Rays (Manta birostris) frequent the site, as well as a myriad of other pelagic and reef fish. Particularly the various species of cleaner fish that draw the oceanic wildlife to the shoal.

    TSRCP is a significant source of environmental, ecological and behavioural research for Pelagic Thresher Sharks, providing research, education and conservation locally, regionally and internationally.

    GUE Relationship

    Through volunteer divers (including myself) TSRCP became aware of Global Underwater Explorers, a non-profit diver training agency focussed on research, conservation and exploration, whose training methods and techniques are uniquely suited to scientific research diving. In 2009 TSRCP became a GUE affiliated project and now provides all volunteer divers with basic training aimed at perfecting the buoyancy, trim and propulsion techniques necessary for a successful research diver.

    Join Us

    I encourage any divers out there to volunteer with the The Thresher Shark Research & Conservation Project. My three months there were amazing—peaceful, eye opening and life changing. The most fulfilling ‘work’ I’ve ever done. I can’t wait to be back in 2011.

    → 2:59 PM, Jul 2
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