T
HE WORLD’S BIGGEST CAVE,
the spectacular Hang Son
Doong in Vietnam, is even
bigger than previously thought –
and the discovery has been made
by celebrated British divers Jason
Mallinson, Rick Stanton and Chris
Jewell.
Oxalis Adventure Tours, the only
company licensed to bring visitors
into the system, invited the three
divers to check out the terminal sump
of remote Son Doong, expressing
gratitude for their Tham Luang cave-
rescue feats last summer (see below).
Their discovery of a new
underwater tunnel connecting Son
Doong with another major cave, Hang
Thung, adds another 1.6 million cu m
to the system’s already vast volume of
38.5 million cu m – a 4% increase.
Previous dye-testing had indicated
a connection between the two caves,
but it had not been possible to
explore it before.
Because most of the previously
known submerged tunnels had been
relatively shallow the divers were
breathing air, which meant that they
had to turn round after reaching
a maximum depth of 77m.From that point they plumbed the
depth below, concluding that the
tunnel could reach as deep as 120m
and continue for another 1km.
Jewell initially dived the terminal
sump to 60m, with the other two men
searching for the way forward the
following day, which was when
Mallinson reached 77m.
Jewell then searched off the line
laid by Mallinson and found the roof
of the new tunnel at a depth of 61m,
though poor visibility made it
impossible to determine its size.
The maximum depth attained
makes Son Doong Vietnam’s deepest
cave dive and extends its length by
60m. The divers had to work in what
were described as challengingconditions, and some of the dives
required nearly two hours of
decompression stops.
The team now plan to return next
April, when water levels will be
relatively low and visibility at its best –
at up to 2m.
The remote Son Doong, which is
Vietnamese for “Mountain River Cave”,
lies in Phong Nha-Ke Bang National
Park in central Vietnam.
Formed as the Rao Thuong river
carved out a limestone tunnel
beneath the Annamite mountain
range over three million years, it was
discovered by a hunter in 1990 –
though he was unable to relocate the
entrance until almost 20 years later.
Howard and Deb Limbert, theOxalis technical directors who
organised the recent diving
expedition, led the British Cave
Research Association (BCRA) team
that first explored the 5km-long cave
in 2009. Inside they found stalagmites
up to 80m high, sections reaching up
to 200m tall and 150m wide, a
passage full of 400-million-year-old
fossils, micro-climates and even jungle
vegetation where dolines, or ceiling
collapses, had occurred.
They were able to claim it as the
world’s biggest cave following
a breakthrough in 2010, estimating
that a whole city block of 40-storey
skyscrapers could fit inside it.
Adventure tours led by BCRA-trained
guides began three years later. DIVER NEWS
divEr 10 divErNEt.com
Honour for Stanton, rights for Netflix, green light for Unsworth
British divers enlarge
world’s biggest cave
Divers prepare to explore the Son Doong river cave.OXALIS ADVENTURE TOURSRICK STANTON, the UK cave-diver who
with John Volanthen led the Tham Luang
cave-rescue team in Thailand last June,
received the George Medal from the
Duke of Cambridge in an investiture
ceremony at Buckingham Palace in May.
Stanton and Volanthen were the
divers who found the stranded Wild Boars
junior football team-members and their
coach in the flooded system.
Volanthen had already received his
George Medal, the second-highest award
for civilian gallantry, and other British
rescuers have been made MBEs.
Talking to press at the investiture, Stanton spoke
of how his fingernails had been ripped off during
the search for the missing boys.
But he said that, while relieved to locate the team,
he and Volanthen had already been thinking about
the next stage, “which was how on Earth were we
going to get them all out, considering what we had
been through to get to them.
“This medal is a reward from the nation for what
we did, but really this is a symbol of the fact that we
successfully rescued all the 13 people. ”said Stanton.
“And that’s got to be the biggest reward.”The investiture coincided with the
announcement that US video-streaming service
Netflix and production company SK Global
Entertainment had bought the rights to the cave-
rescue story from 13 Tham Luang, a company set
up with help from Thailand’s Culture Ministry to
represent the interests of the boys and their coach.
Families of each of the cave survivors are
expected to be paid some £70,000 under the deal,
while 15% of profits will be donated to disaster-
relief charities. An independent feature film about
the rescue called The Caveis already set for releaselater this year.
Meanwhile a US judge has overturned
an appeal and set a trial date of 22
October for Elon Musk, the billionaire
entrepreneur who accused British diver
Vernon Unsworth of being a paedophile
during the cave-rescue operation.
Unsworth was later made an MBE for
his part in the rescue, and the court
decision allows him to proceed with his
defamation lawsuit against Musk for
what he describes as “unlawful,
unsupportable and reprehensible
accusations”. He is seeking around
£60,000 in damages.
After Unsworth had dismissed as a “PR stunt”
Musk’s offer of a cave-going mini-submarine to help
in the rescue, Musk retaliated by tweeting that the
Thailand-based diver was a “pedo guy”, and later
made further allegations in similar vein.
Musk had attempted to dismiss the lawsuit on
the grounds that his statements had been not a real
accusation but an over-the-top insult that should be
categorised as “protected opinion” under the
Constitution’s first amendment. Los Angeles district
judge Stephen Wilson disagreed. The 2018 Tham Luang cave-rescue base.