Hopping my way to full cave...

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

AN/Helitrox with James Blackman of Miami Technical diving

This course was delayed a couple of times. But we finally completed it Independence Day (or Treason Day for the Brits like James) weekend 2020, with the first weekend being in early June.


It is only treason if you lose!! :D
 
In Miami to make attempt number 2 at AN/Helitrox. I have my sidemount gear and took some Bonine we will see how this shakes out. Though apparently it has been Lake Atlantic for the past week hopefully it holds until Sunday.

I spent most of the last week in Pompano teaching a trimix class. The weather was fantastic down there, but the currents varied. On one dive we drifted 5 miles during a 30 minute deco and our exhaust bubbles got sucked down into the holds of the wreck at 160'. On another, we drifted maybe a whole 50 feet on a 40 minute deco.

Water on deco was super warm, 86°. I had to pop my suit several times to keep from overheating.

Hope your class went well.
 
I spent most of the last week in Pompano teaching a trimix class. The weather was fantastic down there, but the currents varied. On one dive we drifted 5 miles during a 30 minute deco and our exhaust bubbles got sucked down into the holds of the wreck at 160'. On another, we drifted maybe a whole 50 feet on a 40 minute deco...

Wow, that's really fast :), much faster than I have ever gone in SE Florida
 
Sounds crazy, it is bad enough to hide from a normal current, would be crazy with the various fighting currents.
 
So far this week I’ve learned to avoid doing a reg switch in the halocline, unless you want a salty taste in your mouth for most of the rest of the dive.
 
Just finished up six days of diving in Mexico. The caves here are amazing. But not only did I enjoy diving here, but between a week here, and my boat diving for the AN/Helitrox course I feel more confident as a sidemount diver. I have a better understanding of using my gear in a wide variety of situations, and what places I can fit into.

Well in a couple of weeks I will back to flow and deco. I will finish up the AN/Helitrox course sometime next week after I get caught up with work.
 
Preface: I am writing this almost a month after the course, our dive planning was more in depth including calculating turn pressures, lost gas planning, and comparing Multideco's numbers with Shearwater's (would be nice if Shearwater released a dive planning app using the exact same settings as their computers). So my dive plans are more summaries than the actual dive plan.

Day 3 Dive 2:
Since I only had more pair of HP100s, and mixing gas took a while we decided to stay a little shallower and just top my HP100s with air. Per the calculator that diluted them down to 20/17, and the oxygen tester confirmed the oxygen content, but I kept the computer programed for 20/34. In the future I am going to get my own helium tester.

Dive plan (IIRC)
110fsw for 40 minutes with a total run time of 69 minutes
133cuft of back gas and 12cuft of deco gas

Back to the Spiegel, but this time on the slow boat so it took a while. Gearing up I decided to try putting both tanks on before back rolling, which ended up being a great idea because the current that was below the thermocline on the previous dive had come all the way to the surface. I grabbed the granny line, and got everything situated pulled myself to the mooring line where I did a bubble check on my instructor. Back down to the wreck, he handed me the deco bottle, I donned it, and then he said time to dump them in a hidden area near the mooring line. So off it went. We swam around staying out of the current as much as possible. Once we reached our desired max TTS, and made our way up the mooring line for 20 minutes of deco. The current really was ripping, when I did my gas switch I wrapped my arm around the mooring line. And during deco I was switching back and forth to even out the workout on the arms so one wouldn't be off gassing more than the other.

I thought that the deco drills were being canceled because I was almost done and he still hadn't signaled to do them, so I asked him if he wanted to do them. He signaled go ahead, first was feathering the valve, again a another non-issue as I had done it as part of my cave training. The next was buddy breathing, which was simulated, I would take a couple of breaths, and handle him the reg, and he would take a couple of breaths on his deco reg, hand it back, and continue back and forth for like a minute. No issues doing the drill, but I must confess it would take a whole stack of issues before I would even consider buddy breathing a deco bottle.

Anyways finish up deco and back on the boat. The small boat is low to the water with a ladder on the stern so that made handing up gear easier even with the current. Get gear situated and did a debrief, I mentioned that I thought we weren't doing the drills and he said he forgot to mention that it would be after deco was cleared. Get back to the dock, get gear sorted, and labeled our tanks with our desired fills; I just labeled mine top with 30%. After we get back to the instructor's house we sat down and went through the standards to make sure that we had all the drills required by the standards done. The only thing remaining was the breath hold swim.

Dive Profile:
Dive time: 71 minutes
Bottom time: 67 minutes
Average Depth: 67 fsw
Max Depth: 110 fsw
Screen Shot 2020-08-01 at 4.42.49 PM.png


Day 4 Dive 1:
Final dive, I wasn't feeling like a lot of deco so I proposed we go down to the well deck for about 25 minutes and see what is down there as I've never gone inside. That we would keep our TTS below 20 minutes. We get our tanks and test them 25/5 and EAN75 for deco.

Dive plan
120fsw for 35 minutes with a total run time of 58 minutes.
124cuft of back gas and 10cuft of deco gas

Back on the small slow boat, splashing was much the same as the last dive, but no current to fight. After getting down to the wreck firsts things first was knocking out the final skill that we had to do. Of course there was no current to help me. Surprisingly hard to do that breath hold swim in tech gear, but on attempt two I was able to get it. And of course failing the drill the first time emphasized avoiding going too far from my buddy unless I can help it. We make our way down to the well deck, there is a surprising amount of life in that dark zone. After "exploring" there we make our way up and forward on the wreck to the bow and the capstan room (or is it called the chain locker either way it is where the motors are for the powered capstans). I get close to our planned max TTS, and start working our way to the mooring line to an uneventful ascent. And a really easy one because we had no current or wave action.

Dive Profile:
Dive time: 63 minutes
Bottom time: 61 minutes
Average Depth: 71 fsw
Max Depth: 113 fsw

Screen Shot 2020-08-01 at 4.42.38 PM.png


Course thoughts:
I can't say I learned a lot, as a lot of the basics of deco diving are covered in Florida cave courses. But I did notice that I didn't get foggy on the deep portions of the dive, when normally I feel it once I hit about 120fsw. Due to costs helium is probably a once in a great while cost only for when I am going past 120 feet. Out of the dives I want to do in the near term only the Mighty O to do a lap or two around the flight deck with a DPV and maybe peer into the hanger if the vis is good, and going to see chicken rock in Buford (after full cave) are dives I am thinking I will do on helium. But any regular use for helium will wait until I finally buy a rebreather. But even though helium use will be sporadic I feel that this course puts me in a good position, I have access to helium if I need it but the limits prevent me from doing anything crazy as going deeper with OC requires a lot of more tanks and planning than I think I am even remotely ready to do.
 
Mexico Trip:
I'm not really planning to go over the entire trip, because most of it would be "It was really cool." While my AN/Helitrox course helped me figure out the best ways for me to sidemount off a boat. My Mexico trip helped me understand how to sidemount AL80s using my rig. Which means I get one of the advantages of using a sidemount rig being able to pick up two random standard tanks and dive redundant with them. Diving in Mexico is often like diving in Upper Orange Grove, except if you accidentally hit something you aren't just leaving a mark on random limestone or silt but potentially damaging a decoration that took thousands of years to form.

Also I would never want to lose the line in Mexico, some of those chambers are so large that you could probably use up an 800 foot reel trying the find the line. And often have other lines crossing the chambers which means you can find a random jump line and not the line you were following. Not only that but some of the chambers were very very vertical with the line somewhere in the middle. And you could easily swim above or below the line. It was also my first experience doing a dive in part or whole within a siphon.

Finally being that it was guided it allowed me to concentrate on being a proper number 2. Checking placements and tie off, popping them on the way out. Particularly with many of the caves we dive where flow precludes that, or we simply don't run a primary reel.

Carwash - Shakeout dives and visit the downstream section
Nohoch - Showing me large caves, and showing me that Mexico has flow when we went downstream
Tajma Ha - I requested to visit this cave, on the 15th because it would be two years after my first cenote tours, and we did this cave as dive 2. People call this a training cave, but the Chinese Garden line was amazing.
Xu-lo - A sidemount only cave

Overall it was a great trip, the caves are beautiful, and the shallowness meant that we could dive 3-4 hours a day with no significant nitrogen loading. I really want to go back.

Video from the dive in Xu-lo (I didn't put my rig on quite right another thing to fix):
 
Completed Rescue today with a local shop. I'm not sure what to think about this course, TBH other than doing rescue breaths in water, I don't feel that I actually learned much.
 
http://cavediveflorida.com/Rum_House.htm

Back
Top Bottom