News
That’s wrong: misconceptions about overhead diving
By: John Bentley & Brian Shreve
The interwebs are a great place to pick up some great, and some not so great, information. Internet cave divers seem to enjoy spouting off opinions based loosely on nothing. This is particularly scary considering the fragility of the cave community and the necessity for standardization in cave diving. Spend a little time on the various scuba related websites, and it’s amazing some of the just plain wrong things you can read!
Here are just a few of them we’ve recently found:
The Rule of 1/6th isn’t appropriate for gaining real experience
This is, unfortunately, a popular one in the North Florida area: The idea that 1/6th doesn’t give the Intro Cave diver enough distance to utilize their newfound awareness, conservation and buddy skills. That’s just not the case. 1/6th gives adequate gas, even for the biggest gas guzzler, to get acquainted to a cave system in a way that exposes them to overhead stress with emphasis on line awareness, buddy procedures, communication, and gas management. It essentially eliminates navigation stress through mainline navigation only, reduces time/distance stress and eliminates most decompression obligation stress.
If 1/6th diver’s gas consumption rates aren’t adequate for getting a few hundred feet into the cave that shows that their comfort level, fitness, and streamlining are not to the level needed to be that far into a cave anyway. While all divers breathe at different rates, and that’s a physiological issue, even the best trained divers double their gas consumption rate under stress. Putting a high volume breather further into a cave without mastery of stress management is asking for trouble.
Visual Jumps are OK
It’s only 3 feet!
This cave never silts out!
I’m familiar with this passage…
Holy moley, no! This one defines all logic. The time it takes to install a jump or gap, a matter of seconds, nullifies all reasons that this would be ok. All overhead dives should be planned for a total loss of visibility, whether through siltation, total light failure or mask loss. If viz is gone finding the gap will be difficult, objectively more difficult than following a line.
Primary lines are optional in tourist caves
This system will spit me out if I’m lost!
Close to open water is close enough!
This one goes back to the previous point. Just no! Tourist caves, like Ginnie and Peacock, that don’t have a line that goes to open water, are no safer than a virgin system. A cavern full of students can quickly make Peacock impossible to navigate. Plenty of individuals have perished in the forward section of a system because they couldn’t clearly find an exit. Just to clarify – If you’re in trouble, running low on gas after a reg failure in low vizibility, do you really want to hit the end of the line, let go, and hope for Mama Ginnie to spit you out? If the answer to that is yes: please, please, take up racquetball instead of cave diving.
It annoys everyone when caverns are a mess of lines, and yes, sometimes that makes it more dangerous. The only solution for a clear exit, where the line runs to the open water, is for cave divers to speak up and have lines extended to open water. This is an issue with land owners not properly restricting access to non-overhead divers. If the site is not open water appropriate (Ginnie for example) then it needs to be restricted to overhead divers only and the guideline should be extended to open water to prevent too many lines. Issues like this are very isolated to certain sites in North Florida and, despite the ease of fix, have spawned an alternate pattern of thinking towards continuous guidelines in cave diving. While every cave is unique and beautiful no cave merits entry without the ability to very easily navigate to the surface with visibility loss.
The Rule of 1/3rds is always appropriate
This is normalization of deviance at its best. The rule of thirds is not always appropriate. When exerted you will use substantially more gas. Long strenuous swims using substantially more gas, or possibly gas sharing, will not work with the rule of thirds. Stages do cause drag and aren’t always appropriate but with long swims in low flow systems they’re a necessary parachute. The “Grand Traverse” in Peacock is often done on thirds and while that seems appropriate to some the margin for error is little with only the gas in a couple sets of mains. A setup dive for longer swims or scooters should include a stage cylinder(s) drop for use as a safety cylinder. This goes back to the basics of dive planning and gas management. We’ve seemed to have forgotten that there are reasons behind the 1/3 rule.
These are just a sample of researched and proven techniques being put to the wayside for stories being shared between divers. The data pools aren’t huge in cave diving, but they’re large enough to set our safety standards. Ignoring these basic guidelines puts us all at risk.
To find out more about International Training, visit www.tdisdi.com.
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The IR-50 is the top regulator for advanced and experienced divers. Natural breathing is the essence of this regulator.
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Renowned anti-whaling activist Paul Watson has been released from custody in Greenland after spending five months in detention. Denmark’s Justice Ministry rejected Japan’s request for his extradition, citing insufficient guarantees that his time already served in custody would be credited against any potential sentence.
The 74-year-old Canadian-American was arrested on July 21 in Nuuk, Greenland’s capital, when his ship docked to refuel. His arrest was based on a 2012 Japanese warrant related to a 2010 encounter in Antarctic waters. Japan alleged Watson obstructed operations and caused damage to a whaling research ship during efforts to disrupt illegal whaling. Watson has consistently denied these claims, maintaining his commitment to marine conservation.
Denmark, which oversees extradition matters for Greenland, concluded that while the legal conditions for extradition were met, the lack of assurances from Japan regarding time-served credit made extradition untenable.
In a video shared by his foundation, Watson expressed gratitude and relief, saying, “After five months, it’s good to be out… and good to know they’re not sending me to Japan.” He added that the most difficult part of his time in custody was being separated from his two young sons.
Watson is a pioneering figure in marine conservation, known for founding the Captain Paul Watson Foundation in 2022 after decades of activism with the Sea Shepherd Conservation Society. His bold efforts to defend marine life have earned him widespread support, including from celebrities and conservationists. His work has also been featured in the acclaimed reality TV series Whale Wars.
Watson’s lawyer, Jonas Christoffersen, praised the decision, stating, “We are happy and relieved that Paul Watson is now free.” He added that Watson is eager to reunite with his family and continue his vital work.
The arrest occurred while Watson’s vessel, the M/Y John Paul DeJoria, was en route to the North Pacific with a team of 26 volunteers to intercept a Japanese whaling ship. His foundation described the arrest as politically motivated and emphasized that Watson’s actions were focused on ending illegal whaling practices.
Japan resumed commercial whaling in 2019 after leaving the International Whaling Commission, asserting that whale meat is a cultural tradition. Conservationists, however, continue to challenge these practices, highlighting their impact on marine ecosystems.
Despite the challenges, Watson remains steadfast in his mission to protect marine life and bring attention to whaling practices. His dedication to ocean conservation has made him a globally respected advocate for the environment.
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