Playing shadows on the wall: PADI Cavern Diver Course Report

Introduction

I took a 6-week holiday to Florida, and my aim of the holiday was two weeks of solid diving, followed by three weeks of being with my family - after all they did pay for the flight! I was taking $2,000 with me to Florida, $1,500 of it to spend purely on diver training. Now I am a lucky guy! My diver training has been carried out by SCUBA West, in Tampa Bay, from OW to MSD, my instructor is Nickol White.

Day 1

Morning

I had been in Florida now for more than a week I still haven't acclimatised. I was wearing beige shorts and a white shirt thinking that will shield me from the majority of the heat, nice mentality but not so! It was 105 oF at 10:30am and was set at that temperature until around 3pm.

PADI doesn't have any official manual for the cavern course, the only way they manage to do it is if the instructor is trained as Full Cave. So it was very much a course based on experience.

We wandered over, or rather rode over, from the SCUBA West shop to the grotto across the road all of 50 yards! But having two twinsets - my Double-104's (pressured to 3000 PSI to make them into 130's - equivalent to twin-15's - someone left them attached to the 3500 PSI bank a bit too long! Hose pipe was on hand to keep them cool though!) And filled with nitrox. The instructor’s twinset - Double-High pressure-100's- equivalent to twin-12's) as well as Ian's single 104 weighs a lot and I saw the Gator and I couldn’t be bothered to carry it so I chucked everything in - two twinsets, one single, four kit bags and a bag of HID torches and went over!

I must say, If your at the grotto and not stood on the concrete part, don't stop for a second, the ants are huuuge and will bite through even the thickest of northern-English skin! My feet had red sores for days after!

First thing - compass work - I hadn't really used my compass ever since I was trained to use it! But I managed to do quite well and can navigate to land within a foot of where I want to be so it’s sufficed. Nickol's brother who came along on the course to make up a team of 3 (and to get a free course) struggled a bit but got the gist of it - I can never remember if I add or subtract when I want to make a turn!

Next thing - reel work - this was fun - especially since I got to use my shiny Pathfinder 400 that I've never used up till this point - Nickol showed me how to make tie-off's and two different ways of doing them, i.e. if you can pass your reel around the object or not!

Laying the line was ok and we ended up tying off to the posts of the shelter, a bin (bad idea - rotting food with maggots crawling out made me change my mind soon after making the tie), the gator and a breeze block. Now the fun part - leave the reel and follow the line back "OKing" it - easy enough to follow back to the start, now I had to go back to reel "OK-ing the line" and with my eyes shut.
I would love to have known what it looks like a 6ft4 inch British bloke shuffling his feet moving half a foot a time with his hand out in front of him feeling for objects must have looked like. I came across a tie off point - now Nickol had put another line in the way so I had the trick of running my figures over the line trying to find the "exiting" line - I spent about 5 mins doing this as I wanted to be sure to follow the right line - you have to think 5 mins making sure you go the right way out of a cave, or go the wrong way and drown.

Carried on and I inevitably hit my head on something - now I don't usually curse or swear that much unless I've had too much of the devils drink or am really angry but cracking my head on the roof of the shelter made me take the lords name in vain a few times, it was made funny when I ended up tripping over the line I just laid and fell about 3 inches from a Fire Ant's nest - even Nickol had to laugh - after all when I swear the Scottish accent part comes through. Posture regained I navigated the rest of the course with few difficulties.

Afternoon

Happy with my "dry" performance it was time to hit the water - to me, 85 oF water is quite warm, but still cooler than the air so I loved it, Nickol took 5 mins to get complaining it was cold!
I was also wearing a 3mm wetsuit so I was cooking. I know I wasn't balanced at all - double 104's, 6lb stainless back plate (I brought it with me from the UK for use with my dry suit!) meant a very heavy rig and even the Explorer 55 wing struggled - it had to be almost full just to float the kit! Thankfully I am a buoyant person so when underwater the wing only had to be about half full. Still wrong I know but let me continue.

Hudson Grotto is a sink hole, we dropped to the 20ft platform where a stage bottle of 100% o2 was left - Nickol wanted me to feel carrying a stage since it would be me carrying it in Manatee should things go tit's up and we need extra gas for deco etc

The o2 was left on the 20ft platform and we got ourselves comfortable and swam over to the wall. At the wall I was to run a line from a suitable tie off point and make 4 tie off's.

The limestone structure of Florida meant tie off's were in ample supply and I made a sufficient course - I came across several other line's that were laid so I knew that would be interesting later on.
I laid the line and then we had to return to the start following it no problems. Then we had to follow the line by OK-ing it. Again no problems. Finally I had to follow the line with eyes shut. Definitely more complicated and much slower. It was at this point that I realised that rule of thirds is not very conservative at all. After taking 5 mins to do a course that took me about 2 mins to follow when OK-ing it you realise you need a bigger reserve.

Next were out-of-air drills. When teaching PADI Cavern, the instructor must be in full cave kit i.e. Hogarthian rig. I was also in the DIR kit setup, however Ian came along in his single recreational set with standard length reg hoses and "octopus" when it came to myself and Nickol air sharing - it was a piece of cake - 7ft hoses make life a dream. But watching Nickol and Ian air share was a different story. Not an issue when Nickol donated as it was usual scenario donor at the back. My only issue was that because my wing was so full I struggled to deploy my hose fully. I managed to get my reg to Nickol, and then I had to fight to get the rest of the hose from behind the wing.

But watching Ian donate to Nickol was painful to watch and gives you plenty of reasons why long hoses are advocated in caves or other over-head environments. Ian had to swim on his side so that his octopus could reach Nickol - their swim was painful to watch. You wouldn’t get through a restriction like that.
Now back to me, OOA and following the line. Crickey - it’s not so much difficult just hard work. Nickol was behind me in touch contact and I was leading following the line - I must say we simulated zero viz too - I was only giving the occasional fin kicks because I was struggling to deal with the line. When it came to a tie off - Jeez!! - The tie off with multiple lines caused no end of problems; simulated zero viz meant that I had to figure out which line of 3 to follow. 10 minutes I spent there before determining the right line. Just as I realise which line to follow, the limestone crumbles in my hands and a block of limestone about the same size as a small suitcase falls - I spent the next minute looking for any bubbles praying no one was deep. There wasn't.

(On a deep dive - using nitrox 27 at 140 feet - we found that rock and the silt cloud extended for hundreds of feet in every direction - a rock falling from 30 feet to 140 must have been going a hell of a speed with a lot of momentum).

Again, using 1/3rds, and taking 10 mins to follow a line that took 2 mins to lie makes a sobering thought. If it were a real cave I probably wouldn’t have made it out alive.

By this point we have been in the water an hour and the biggest mistake you could imagine occurs, Nickol and myself are doing the drill again because I wanted to improve my ability and Ian is hovering away from the wall watching us I'm figuring out a tie off and I hear a blood curdling scream through a regulator - I open my eyes and I see Ian swimming over with no reg in his mouth - he's out of air - I donate my long hose and we end the dive - thankfully all the skills were completed and with a bottom time of 65 minutes at 30 feet I did 5 mins of stops.

Everyone surfaced and we found out that Ian had never checked his SPG since jumping in - Nickol gave him a shouting but I got a hand shake congratulating me on successfully passing the open water element of the cavern course.

Day 2

5am - Alarm goes off - I don't do mornings. I'm a student - I like lie-ins
Nickol picks me up at my villa with her brother – I had left my kit at the dive shop and had them fill my twinset and pack the van for today - kits in the back and we mount up for the 90 minute drive north to Manatee Springs.

Drive went well – I spent it reading my Emergency First Response manual for the course next week - we soon arrive - I treat Nickol to free entry as I pay her fee and we drive down to Catfish Hotel - we asked not for Manatee Springs as Nickol knows the flow rate of the water coming out is horrific.
We park up and carry kit to some park tables and set up. I am shown the dive site - first impression - a swamp!!! The "pond" must be about 150 feet across and covered with duckweed. That proved to be a right pain to get out of the kit and ourselves later.

Manatee Springs Entrance

Catfish Hotel Entrance

What you can’t see in that picture is the flow, you could actually see the surface rippling with the flow of water coming out the cave which is in the bottom right corner of the photo.
We kitted up and headed down the steps – having two people in heavy twinsets its not a nice feeling having the wood bow under your feet. The water level was high and I was told about a concrete ledge under the steps - found that very cautiously and found the edge - now I was told to jump as far away as possible as the water is only about 6 ft deep. It’s not a pleasant feeling not being able to see what you’re landing in when you jump but it had to be done and I regretted it straight away.

I landed on a limestone rock and it gave me a dead leg! Thankfully the wetsuit wasn't ripped and I was OK it turned out to be a hell of a bruise and a bit of a graze - I was passed the O2 stage and I helped Ian and Nickol into the water by pointing them to a deeper bit of water with no rocks!

First dive

I started with 200 bar in twin-15s/Double-104’s. The first dive meant that Nickol would lay the line and do a tour and I would observe - using 1/6ths that meant a turn pressure of about 170 bar.

We descended and found a tree running from 15 feet down to 55 feet. Half way down we shoved the 02 bottle under the tree for emergency. At the bottom Nickol tied of the lie to a primary and secondary and we went in the cavern zone. Just before we entered the cavern, Ian bottled it; he didn't like the over-head environment and decided to stay outside.

We plodded on and explored - I was anxious - so my SAC rate was a bit up and we only got to explore the first 30 feet of the cavern. We mostly put our efforts into heading left towards manatee springs until Nickol realised that if we go much further the flow would catch us and push us all the way which would have been a bit much for my first ever cavern dive!

I turned the dive far too soon and I surfaced at 150 bar. Being on nitrox 32 we decided to sit on the surface for 30 mins. We found out that Ian called it quits because he didn't like the over-head environment.

While conducting surface-decompression (don't slate it - it works!) a pair of German cave divers started setting up kit consisting of a pair of 100% o2 deco bottles and a pair of stages. They were kitted up DIR style and when asked I found that they were Cave 1 certified. Although they were German it sounds like they trained in America as they referred to turn pressures in PSI.

I must be said that it made me crack up listening to them; the Germans are very methodical and hearing their procedures, "HID Light ... spark .... Confirmed ... check ... (other person) HID Light.... spark ...confirmed… check" and so it went on and they discussed their turn pressures.

I didn’t understand the mentality of their turn pressures, they chose to do ½ + 200 on the stage, so when Nickol kindly interrupted and asked about their planning they explained they reserve the exit gas of the stage in their back gas should they lose the stage. Made sense.We let them go on their way for 20 more minutes before we went down.

Dive 2

This time I was to lead the dive and lay line into the cavern zone.

Primary tie off

I tied off my primary and second tie off's and continued into the cavern zone, I dictated my new turn pressure to Nickol (again fudged for the flow a bit) I headed towards Manatee again, we found Ze Germans, Nickol realised they were heading to the spring and tried to tell them the way to Sue's Sink, they didn't understand and she grabbed one by the hand and led them over! I found it comical but I sat where I was until she came back.

Looking out from the cavern.

We then headed around the back of the cavern until I found the Grim Reaper sign that  marked the edge of the cavern zone. At this point you are now heading towards Sue's Sink.

At the Grim Reaper sign

Going over this I found how strong the flow is! The passage bottle-necked at this point and jeez it was tough to move! I thought of the flow in terms of fluid dynamics and guessed that the weakest flow is at the edges in the corners so I stuck to there while Nickol went straight through the middle. She made little progress and some turbulent water threw me to the roof of the cave and an almighty metallic ring. I stopped still for what felt like a life time listening for the violent flow of bubbles that would erupt from a 1st stage getting sheared off - it never came - when I reached back I felt that the rock was no where near by valves and the rock hit further down on my lower set of bands. Phew!
I swam over to Nickol who had just got through the bottle neck - the panic and the effort to fight the flow meant that I hit my turn pressure too early again and surface after a total of 30 mins bottom time. Again over far too early. I surface with 100 bar remaining. Given that this meant I had half gas of my twinset, it was the same as diving a single, so we used 1/3rds on the remaining gas - expecting to surface with about 50 bar.

Final dive

I was determined for a good dive, each successive dive meant slightly longer bottom time and more penetration. We dropped straight down on the log and I made the tie off's and headed straight in the cave. I found a log just before the grim reaper sign so I tied off here, I saw that the Germans were still in there and figuring that they would be in longer than we would, and they would have to pass me to get out I laid my line on top of theirs. This turned out to be an excellent idea.

I pushed past the grim reaper and stuck to the sides of the cave - the flow was picking up throughout the day. Once past the "restriction" I tied off again and made a push for a turn in the cave. At this point I was about 70ft in (by PADI rules this is max pen – the PADI rules dictate a maximum of 150’ from where you are to the surface, so if you go down 80’, you can only travel 70’) but my instructor wanted to demonstrate the edge of daylight zone, so we pushed past the corner another 30ft, we found a split where one headed to Sue's sink and I don't know about the other - we carried on another 20 feet or so and stopped at the wall - I was around 150ft in we faced the way we came and covered our lights - there was no ambient light around here - so we were beyond the cavern zone - this lesson was to show I am not qualified to go further in. I happened to hit my turn pressure too 60 bar ish

We headed back - the flow was monstrous and it meant I didn't have to kick and I had to swim to fight the current while I untied the tie off's.

Laying line at the back of the cavern.

Heading back to the grim reaper meant that I was almost out and I felt almost upset - cave diving was my thing I knew it would be a long time till I was in a cave again - Nickol pulled out my camera and snapped a few pictures of me - she put it in video mode and recorded me coming out of the cave untying as I went. The video stopped after 2 mins and at that point I bird-nested my reel - a lot of slack came and I tried to reel it in too fast and it didn’t work out.

Also when I reeled in my line, the line laid by the Germans had come lose and floated up with the risk of getting cut on the sharp edges of some rocks. Nickol quickly moved to secure their line under a log.

I was 65 feet down with 55 bar left - Nickol came over - probably cursing - and tried to undo the reel - we spent 15 minutes there - I snapped off some pictures of the local fish during the hang.

Catfish

Another fish

I watched my contents gauge dropping - 55.... 50.... 45.... 40.... at this point Nickol gave up and we made the ascent - I was worried that my regs would cease operation as I knew they needed a minimum pressure just to operate - we made the ascent to 15' - at 25' I had a horrific reverse-block. I had to drop to 30' and made an ascent at about 3' per minute. I did this through the 3 minute stop dictated to me by the tables and my Suunto computer (I wanted to keep it happy too!)
I probably should have gone onto Nickol’s long hose at this point but figured that I am very close to the surface so I would be OK. My instructor sat with me throughout the ordeal.

Nikol - my instructor

The ascent to 10' was painful I had to keep stopping, descending and then recommencing my ascent - I didn't want to look at my gauge as I was bothered it could panic me - I surfaced 5 mins after the stop was completed - with 20 bar remaining.

Soon after we surfaced the Germans exited, completed their decompression and surfaced. After having a quick chat we quickly noticed they were out of breath. They were equipped with Double-104’s (pressured to 3000 PSI – therefore they were double-130’s, twin-15’s), an AL-80 stage and an AL-40 full of O2 dedicated for decompression and they only managed 600ft of penetration.

I had passed the course. A total of 2 ½ hours of bottom time and 4 hours of dry practising and I am now a cavern diver. I was given 3 line arrows as a gift. I continued on the rest of my holiday to complete a total of 10 courses : Nitrox, Deep, Rescue (very difficult but very rewarding!), EFR, Cavern, Photography, Peak Performance, Multi-Level, Night and Master SCUBA Diver.