Planning for two dives on doubles?

[DogDiver]

4000 PSI is the test pressure on those tanks. Filling them all the way to test reassure is probably not a good idea, both for the fill guys health and the tanks. Not to mention what might happen in a car, in FL heat, in traffic. To each his own, I guess.

Low pressure Faber 85’s service pressure is 2400 psi. Obviously you have never dove in North Florida cave country. Standard fill here is between 3600 and 4000 psi for any steel cylinder. Most folks use double burst discs in the DIN valves. I prefer single burst disc assemblies rated for 5200 psi. when I’m in the Keys I tell the dive master not to look at my SPG. Saves grief.

 

[boulderjohn]

Will someone that has completed the full Deep Diver Specialty certification course be allowed on these, or do they require the Advanced card regardless?

Low pressure Faber 85’s service pressure is 2400 psi. Obviously you have never dove in North Florida cave country. Standard fill here is between 3600 and 4000 psi for any steel cylinder. Most folks use double burst discs in the DIN valves. I prefer single burst disc assemblies rated for 5200 psi. when I’m in the Keys I tell the dive master not to look at my SPG. Saves grief.

Then there was the time I had my double LP 108s filled in South Florida, and the guy who filled them said one of the burst discs had been leaking slightly, but he had fixed it. I thought he meant he had tightened it. I did not know he had instead replaced the disk, putting in one intended for LP tanks, until I had them filled in cave country. I'm sure the people who were in the Cave Adventurers shop that day will long remember it.

 

[halocline]

Low pressure Faber 85’s service pressure is 2400 psi. Obviously you have never dove in North Florida cave country. Standard fill here is between 3600 and 4000 psi for any steel cylinder. Most folks use double burst discs in the DIN valves. I prefer single burst disc assemblies rated for 5200 psi. when I’m in the Keys I tell the dive master not to look at my SPG. Saves grief.

I’m definitely aware of cave fills. There’s a big difference between 3600 and 4000 PSI in terms of stress on the tank. LP steel tanks are designed to be pressurized to 4K once every five years, in a water bath, for a few seconds, to test structural integrity.

Besides, isn’t this thread about diving in the FL keys? OW, with a maximum depth of probably 50 ft? Do you really need to bring 257 cft of gas for a dive like that? Is it worth the wear and stress on your nice LP85s? It sure would not be to me.

 

[bbaydiver2]

As to the original post - as others have said, it could be multiple reasons, including testing the kit out, practicing skills/trim, bored, practicing multi-day days with mixed gas where all you have is air to top off the tanks after the first dive but have to hit a specific mixture for the next dive.

 

[34109411]

Then you dive sidemount and backmount doubles feel like crap underwater in comparison.

 

[NothingClever]

I dived my new HP100 TS today just to confirm no leaks and learn its trim characteristics. At the end of two dives I still had 100 Bar / 1450 psi left. I’ll probably rotate the AL80 TS with 40lb wing to recreational duty (sports car) and leave the LP85 and HP100 TS with 60lb wing (dump truck) strictly for Trimix dives. The HP100 TS is just a bit too unwieldy for plain vanilla warm water recreational dives and stipulates redundancy.

Why do I dive TS for recreational dives? I like the flexibility to see what I want to see without having to think much about gas volume. Also, I like maintaining TS proficiency (LH, SH, can light, flow check, etc).

When I do a ST dive, it’s so easy it feels like it should be illegal. I’d rather feel like that than dive ST all the time and then feel daunted by the weight and ecosphere of TS skills.

 

[lowwall]

I give up. What's TS and ST (single tank?)?

 

[NothingClever]

Twinset and single tank.

My 16 y/o daughter told me I need to work on my hipster skills. I pulled my tube socks up to my knees and said, “ScubaBoard, prepare to behold my badness!”.

TS and ST are probably a pretty good effort for one day.

 

[rx7diver]

I dived my new HP100 TS today just to confirm no leaks and learn its trim characteristics. At the end of two dives I still had 100 Bar / 1450 psi left. I’ll probably rotate the AL80 TS with 40lb wing to recreational duty (sports car) and leave the LP85 and HP100 TS with 60lb wing (dump truck) strictly for Trimix dives. The HP100 TS is just a bit too unwieldy for plain vanilla warm water recreational dives and stipulates redundancy.

Why do I dive TS for recreational dives? I like the flexibility to see what I want to see without having to think much about gas volume. Also, I like maintaining TS proficiency (LH, SH, can light, flow check, etc).

When I do a ST dive, it’s so easy it feels like it should be illegal. I’d rather feel like that than dive ST all the time and then feel daunted by the weight and ecosphere of TS skills.

@NothingClever,

I think I missed the details. Did you dive back-mounted, manifolded HP100's? (Is this what you mean by "TS"?) Were these ocean dives? Were you wearing a drysuit? Did your doubles wing have double bladders?

TIA,
rx7diver

 

[RyanT]

My 16 y/o daughter told me I need to work on my hipster skills. I pulled my tube socks up to my knees and said, “ScubaBoard, prepare to behold my badness!”.

IDK, sounds "tots sus" to me!