GROTTA GIUSTI is a 130-million-year-old cave-system (or “fault system” to be more accurate, but let’s refer to it as a cave for ease) and was first discovered in 1849. Yes, it’s a dive within an overhead environment, but bear with me!
Today, rather than just a hole in the ground, it is located below a rather nice spa hotel of the same name, and situated within the central Italian region of Tuscany.
It’s no coincidence that the spa hotel sits on top of the cave-system either, being that the spa facility largely depends on the “healing powers” of the warm water found within.
I felt a shade out of place turning up at the Grotta Giusti hotel reception desk with my fashionably worn-in dive kit-bag and rather scruffy outdoorsy clothing. Once checked in I was handed a spa robe and hotel-branded flip-flops and my bags were swiftly taken ahead of me to a room overlooking the hotel gardens. Because, of course, I wasn’t here only for the diving.
Once settled in, I could look forward to meeting spa dive-guides Luciano Tanini and Paolo Lenaz, who would be showing me what was what over the next couple of days.
Luciano and Paolo don’t work directly for the hotel, but they’re super-passionate about the diving below it. They run Grotta Giusti Diving, which caters for visiting divers but also, over the past 20-plus years, has enabled them to fully explore the system.
This mutual relationship gives them unprecedented access to the caves, allowing them to open up new routes within them. They also carry unique PADI Spa Diver Instructor certifications, based on a course that they developed with PADI’s approval.

THE HOTEL ITSELF I would describe as a get-away for a quiet, relaxing or romantic weekend. It’s not the kind of place to which I would suggest taking children (for the sake of other guests if nothing else).
Service and dining is impeccable and the list of spa facilities appears endless. The room was huge, with grand windows overlooking a well-manicured garden. Overall, standards reflect the pricing.
The evening after arrival, following a couple of spa treatments and a lounge by the thermal hotel pool, I met the guides again, this time to be briefed on the first of two grotta activities I was to sample – the Grotta Giusti “Spa Flotation Experience” (which is where the non-diving partner gets to join in). The guides described this experience to me as a “dive for the mind”. I changed into swimming shorts, dive-boots and a rash-vest and was led down into the grotta below the hotel.
A short walkway leads to the cave entrance, where a floppy plastic curtain marks the way in – a barrier between the outside world and the underworld.
The first thing I noticed once inside was the intense humidity, which registers at around 98%, with air temperature at 34°C. During the day, the grotta is off-limits to divers and used only by the spa hotel for its guests to relax in, surrounded by the detoxifying properties this under-ground environment is said to produce.
Because of this the area is well-maintained, with a handrail, concrete flooring and carefully placed ambient lighting, set to enhance the grotta’s fascinating natural formations.
These, I learnt, are very different from those found in a “normal” cave, where in this instance what I would have assumed were stalactites and stalagmites are in fact concretions – “hard, compact masses of matter formed by the precipitation of mineral cement within the spaces between particles”.
These concretions take many forms, from super-tall protruding cone shapes to cauliflower-like patterns and even some that resemble human ears. Luciano believes that these features occur only in Tuscany and one other area in Brazil.
Once the path stops, a ladder leads down to the edge of the gin-clear waters and an area called Lago del Limbo (or Limbo Lake).
The flotation experience is basically a chance to enjoy the environment from the water (which also registers at a balmy 34°C), moving about using hands and feet, scrambling while partially submerged from rock to rock and wall to wall.
I was keen to see where the entrance to the beginning of the dive was located, so we floated towards it and one of the chaps shone a torch down into what looked to me like a reasonably narrow hole in the lake’s floor. I have to admit that I may have questioned what I had let myself in for dive-wise at that moment.

AS WELL AS A FUN NON-DIVING ACTIVITY, the flotation experience I thought acted as a great precursor for the actual diving I was to do.
The following evening at 6, with my partner Ana, a bunch of enthusiastic Italian divers and a handful of guides, we gathered in a room for our dive-briefing.
I was glad that I just happened to be sitting next to an English-speaking Italian, who was able to quietly translate the guide’s Powerpoint presentation for me.
The briefing was clearly thorough, which is commendable, but an English version would have been more helpful for me at this point.
There would be 12 divers (including Ana and me) entering the system, and for every four divers, two guides would be present – one at the back and one at the front of each party.
The dive would last approximately an hour, penetrating 150m of passage. Emphasis was placed on gas-management – we would be using only a single cylinder, and only one-fifth of our air would be used on the way in, with the balance saved for the return journey and a decent amount left as a buffer.
The dive-centre also prefers divers to use its equipment rather than their own, because they furnish each diver with a cylinder complete with two first stages and three regulators, which they have set up and ready to go.
Without wanting to sound like a princess here, I really don’t like diving with hire gear, because I know my own equipment inside-out.
However, Luciano advised me that the rock within the cave tends to wreck BCs, so I would be far better off using theirs (they were right, of course).

ONE OF THE MAIN THINGS that sets this diving experience apart from any other with which I’ve been involved is that it is carried out without fins.
Without fins?! Yes, I know, it sounds ridiculous, but believe me, it really does work quite well.
This dive is open to all levels of diver from PADI Open Water (or equivalent), so no cave or overhead-diving experience is required. The removal of fins from the equation means that buoyancy control is not an issue, and our BCs would remain empty of air once we were submerged.
This in turn reduces task-loading. Let’s face it, however many guides and regulators are thrown into the equation, you’ve still got to be comfortable diving within an overhead environment.
And so, with all the usual disclaimer forms signed, we gathered into our prearranged groups and climbed into our preassembled scuba units. Our group was to head off into the lake first, with the others following at 10-minute intervals.
Luciano led the way back down the steps and into the underground lake in the direction of that spooky hole I had seen the previous evening.
Before anyone entered the system proper, each group, together with guides, made for the bottom to become accustomed to moving about without fins, and to check that we were also proficient in what was essentially rock-climbing around the environment.
I’m a keen sport-climber, so to combine this with scuba-diving in one outing promised to be great fun.

WITH EVERYONE IN ORDER we entered the first part of the cave, a reasonably narrow section in the lake floor, past two enormous cones, named Paolo and Francesca.
This stage was to be tackled feet-first, our tanks banging against the rock as we entered the darkness.
We had all been issued with helmets, too, complete with a pair of torches fixed in position. I was glad of the helmet as my head scraped the rock during my initial descent. The torches are really there only to help the guides keep track of their divers rather than for illuminating anything around you. The guides do a pretty good job of that with their own torches, although I’d say it doesn’t hurt to bring your own as well.
Before the dive I had quizzed Luciano about how popular this dive-site had been over the years, and he told me that he estimated that around 15,000 divers had enjoyed the experience over the past couple of decades.
This led me to wonder what kind of mark this volume of traffic could make on the environment, especially with divers walking and climbing rather than swimming through it.
The answer to this question, as I discovered only a few minutes into the dive, was none – so far as I could see. Apart from several lines permanently laid within the system, it felt as if we were the first people ever to enter the place.
I immediately felt comfortable within the cave, and noticed that the water felt neither warm nor cold, as if we were not within a watery environment at all. Could it be that I have discovered the perfect diveable temperature!
Our first destination was a chamber named Beatrice. Here we clambered upwards a short way, eventually breaking the surface and inflating our BCs.
The air in this chamber is perfectly good to breathe, so we bobbed here for a few minutes, enjoying the cathedral of interesting rocky formations.
Once back under water we made our way deeper along passageways, sometimes walking on a thin shelf of rock, sometimes scrambling, but never needing to swim.
After 10 or so minutes of this, we emerged into another chamber, or sump, where again we were able to enjoy our surroundings and communicate in breathable air with regulators removed.

PAOLO POINTED TOWARDS a dry passage that led higher still, and I could make out a fixed rope that disappeared into darkness. He explained that the water level was actually too low to enter this area at present.
Luciano had us all turn off our lights for a few minutes to experience true darkness – I kind of spoilt things slightly here with various LEDs still glowing from my camera gear (sorry, guys).
Time raced past, and by this point we were well into the shallowest part of the cave, but it would be our return journey that would take us to our maximum depth of 18m.
I had wondered how 12-plus people would collectively fit into such a small space, and was very impressed by how well Luciano and Paolo managed this.
Apart from the odd flicker from another diver’s torch from a neighbouring passageway, we didn’t encounter anyone else on our journey.
I had previously had visions of us having to squeeze past a bottleneck of divers entering as we were making for the exit, with people flapping about all over the place, but this simply wasn’t the case.
Another thing that struck me about this dive was the lack of depth perception. I had also wondered what so many divers might had done to the gin-clear visibility, but at no point did we go anywhere near the true bottom, which is indeed said to be quite silty.

AS WE MADE OUR WAY towards the entrance, bubbles roared through the rock from divers in passages below us. Such was the noise that you could have been forgiven for thinking that the ceiling was coming crashing down (yikes!).
It wasn’t long before we were back at the main entrance and greeted once again by Paolo and Francesca, those towering concretion cones we’d seen on the way in. Luciano had told me before the dive that most visiting divers don’t want to leave.
At that point I had been (if I’m honest) a little apprehensive of the whole experience, but by the time we surfaced nearly an hour after entering, I couldn’t have agreed with him more.

FACTFILE
GETTING THERE: Will flew with easyJet from London Gatwick to Pisa and hired a car at the airport. The hotel is in Monsummano 24 miles away, so can be reached by public transport or taxi.
DIVING & ACCOMMODATION: Grotta Giusti Spa Hotel, grottagiustispa.com. Diving can be booked with the hotel, grottagiustidiving.com
WHEN TO GO: October to May, when the water level is sufficiently high.
CURRENCY: Euro
PRICES: Return flights from £130. One night half-board costs from around 143 euros pp. One dive costs 100 euros pp including equipment. The floating experience also costs 100 euros pp. Subsequent dives are possible, exploring further and deeper into the cave.
VISITOR INFORMATION: italia.it