Question Mod3 motivation (wreck or cave)

[Alex Ouroboros]

Conditions sound very nice out there, I’m afraid the uk doesn’t have any real reefs in that respect the closest you get is a critter infested wreck that are fantastic,
as for the Co2 hit side of things am afraid I’m all ears if someone can tell me of anyone surviving a real hit (as apposed a quickly detected slight breakthrough) with even 45mins of deco involved, your quite right the rate Co2 is expelled from the body is so slow the unfortunate diver will indeed chuff like a freight train, I’m fairly certain it only calms down once laying down once topside..
if memory serves there was a Brit diver that worked for sky tv and did underwater video work and had this happen and it was accidentally videod and is / was on YouTube (he’s on an inspo) makes for sobering viewing… I’ll try find a link (but bear with me am a dinosaur)


(My word I actually added it)

 

[Germie]

My motivation for mod3 maybe was not the best. I had a full trimix cert oc and did it just to have no limits anymore. The instructor I choose did not tell me, but he had a employee that was guiding technical dives and promised that employee as soon as there was a good full trimix student he would take him and the student to 100m. So I went to 100m on the qualifying dive of the course. Just a reef on Malta (Gozo, Ras il hobz). So I did my first 100m dive when expecting only go to 75 during the course (of course I was allowed to say no to this dive).
Then I had no limits anymore and I started doing deep dives over 100m on oc, in a time that was doable with the helium prices.
But after a wreckdive to 117m I decided I needed a ccr. So I bought a ccr and 3 months later I signed up for a mod3 course.
The course was done in Austria, only go down, touch and go. Just 80m during the course. But I did the days after the course with a buddy 5 days of dives over 100m to 128m, no long bottomtimes, sometimes a couple of minutes, sometimes touch and go.
Later I used my machine for deep cave diving (122m is my max depth in a cave), but also for deep wrecks and deep walls.

So my motivation for the mod3 course was that I wanted to be able to do the same as I could do on oc. I had no main reason to do the course, just wanted to have no limits. I hate pointing fingers if you dive outside of a cert, and even now I am instructor I will not easy blame people who dive outside a certification limit. I have seen divers with a cert that should not have that cert and I have divers seen without a cert for such depth (or even no full cave cert) that are good divers and will pass a course very easy.

But it is soo easy that you don't have limits anymore, I can sign up for a dive I want without limits of depth. So if I want to do a deep wreck in the UK, I can arrange it, I can arrange a deep mine dive, I can go to Italy and dive the U455 again, etc etc. And that is in my eyes a good motivation to do a course.
A good bailoutplanning and eventually the use of safety divers is part of a GOOD full trimix/mod3 course.

Even on ccr, like on oc, the limit is not the bottomgas most times, but the decogases. This does not change. Plan 20 minutes on 110m depth oc and if you have to do a BO after 20 minutes and see where the bottlenecks are. Then consider if you can do it with team BO or even need safety divers.

I would say, do a mod3, you will not be a worser diver after it. And you won't have discussions if you go to a wreck at 75m where you now maybe get discussions.

 

[kensuf]

Conditions sound very nice out there, I’m afraid the uk doesn’t have any real reefs in that respect the closest you get is a critter infested wreck that are fantastic,
as for the Co2 hit side of things am afraid I’m all ears if someone can tell me of anyone surviving a real hit (as apposed a quickly detected slight breakthrough) with even 45mins of deco involved, your quite right the rate Co2 is expelled from the body is so slow the unfortunate diver will indeed chuff like a freight train, I’m fairly certain it only calms down once laying down once topside..
if memory serves there was a Brit diver that worked for sky tv and did underwater video work and had this happen and it was accidentally videod and is / was on YouTube (he’s on an inspo) makes for sobering viewing… I’ll try find a link (but bear with me am a dinosaur)


(My word I actually added it)

I've seen a couple of co2 hits and taken one myself. All three were mushroom valve problems. The amount of gas a person goes through is pretty impressive, but it eventually gets under control.

 

[Alex Ouroboros]

I've seen a couple of co2 hits and taken one myself. All three were mushroom valve problems. The amount of gas a person goes through is pretty impressive, but it eventually gets under control.

Did you have deco in front of you ?

Glad everything was sorted and you all came away unscathed

 

[kensuf]

Did you have deco in front of you ?

Glad everything was sorted and you all came away unscathed

Yes on 2, no on 1.

The first one was pretty quick into the dive, some gunk (duckweed for those that know what it is) got into the mushroom valves and they stuck open - no deco on that one.

The other two involved deco and both were caused by accidentally flipping the baskets upside down while replacing the mushroom valves on a shrimp. It caused the mushroom valves to stick open, but in both cases it happened ~40-60 minutes into the dive. Mine happened about 4000' back in a cave, the other happened to someone around the time we were on our 40' stop.

 

[Germie]

I had a CO2 hit last februari. It was because my drysuit was flouded and all was ok, till we swam at 65m in an old mine and I had to follow the tunnel upwards. All the water came into my legs and normal swimming was impossible. It became then also very cold. So I tried not to stirr everything up, and then I was out of breath.
I was really counting the last 45 minutes of deco down.
AND they had in this mine an escape way for emergencies, you were only allowed to get up there in an emergency. This was around 120m from the entrance. I have really thought that I would use that. But at the end decided I could swim the last 120m at max 8m depth to the normal exit.

After the dive I had a very very bad headache which lasted till deep in the night. The next day I was tired, but further ok again. So we did the same dive again, but without a flooded suit (neckseal was the problem with just a very small leak, I took another drysuit the next day).

Never found anything wrong with the machine, new sorb, no things flooded in the machine, no mushroomvalve problems, not the most important O-ring from an inspiration moved. So here it was the flooded suit and the long way swimming back at depth, together with the watertemperature, only 8 degrees C.

 

[Alex Ouroboros]

Yes on 2, no on 1.

The first one was pretty quick into the dive, some gunk (duckweed for those that know what it is) got into the mushroom valves and they stuck open - no deco on that one.

The other two involved deco and both were caused by accidentally flipping the baskets upside down while replacing the mushroom valves on a shrimp. It caused the mushroom valves to stick open, but in both cases it happened ~40-60 minutes into the dive. Mine happened about 4000' back in a cave, the other happened to someone around the time we were on our 40' stop.

Bloody hell that is not a good day at the office..

 

[Alex Ouroboros]

I had a CO2 hit last februari. It was because my drysuit was flouded and all was ok, till we swam at 65m in an old mine and I had to follow the tunnel upwards. All the water came into my legs and normal swimming was impossible. It became then also very cold. So I tried not to stirr everything up, and then I was out of breath.
I was really counting the last 45 minutes of deco down.
AND they had in this mine an escape way for emergencies, you were only allowed to get up there in an emergency. This was around 120m from the entrance. I have really thought that I would use that. But at the end decided I could swim the last 120m at max 8m depth to the normal exit.

After the dive I had a very very bad headache which lasted till deep in the night. The next day I was tired, but further ok again. So we did the same dive again, but without a flooded suit (neckseal was the problem with just a very small leak, I took another drysuit the next day).

Never found anything wrong with the machine, new sorb, no things flooded in the machine, no mushroomvalve problems, not the most important O-ring from an inspiration moved. So here it was the flooded suit and the long way swimming back at depth, together with the watertemperature, only 8 degrees C.

As frightening a situation as that is that’s not even anything wrong with the breathing loop just as you correctly deduced post dive it was breakthrough.