LP 95 too heavy if wet?

[Mouth Breather old]

Hello,

I want to hit 1000 psi about the same time as my AL80 buddies but I use more air than they do. So I'm going to unload my AL80 and go a little bigger. I'm 6'1" 200 lbs, wear a 7mm wetsuit, and use a back inflate BC.

I read some threads "warning" wet divers about big steel tanks and the fact that they may have too much unditchable weight. As I see it, with no air in my BC (punctured bladder) and a full "big (larger than 80) steel LP tank I want to be able to ditch enough weight to be able to make a safe slow ascent right? So what is the best way to get the extra gas without being too negative?

Thanks

 

[Jonathan]

I'm a little shorter than you and about 25lbs heavier - I still needed weight (about 6lbs) when using a 95 and a 3mm shorty - don't think you will have a problem in a 7mm full suit.....

 

[MikeS]

Mouth Breather once bubbled...

I read some threads "warning" wet divers about big steel tanks and the fact that they may have too much unditchable weight. As I see it, with no air in my BC (punctured bladder) and a full "big (larger than 80) steel LP tank I want to be able to ditch enough weight to be able to make a safe slow ascent right? So what is the best way to get the extra gas without being too negative?

Thanks

I don’t think it would be a good idea to drop your weights at depth even in the case of a BC failure. If you started out neutrally buoyant at depth you would become more and more positive as you ascended and your suit expanded, no way you can control that ascent. Perhaps someone will correct me here but I can see no situation, other than body recovery, including a BC failure, where dropping weight at depth is a good idea.

I think that better questions are:

1. Can you comfortably swim up from depth with an empty BC? I can easily with my 7,6,8 semi-dry and an HP120. I tested it at 90 ffw.

2. Can you drop enough weight to become positively buoyant at the surface?

I also carry a surface marker with an advertised 40 pounds of lift as a backup.

Mike

 

[Rick Murchison]

The difference in a PST LP 95 and a standard AL 80 is 12 pounds in buoyancy. If you're carrying more than 12 with your AL 80 you'll still have ditchable weight with your '95.
I suspect you are, and so I expect you'll be just fine.
Rick

 

[raxafarian]

I was diving 34lbs with a jacket bc and an AL80. Now dive 20lbs with a SS bp/wing and AL80. Switched to LP95's and 14lbs on belt.

The lp95 is around 8-9lbs more negative than an AL80 when full.... about 6-7lbs more negative when empty.

I had to move all my weight belt weights to the front pockets to feel stable... otherwise it felt like I was going to continue rolling if I turned on my side. Have to keep the tank as low as possible (top tank band at the start of the slope to tank neck). Once I made these changes with the LP95, all is well. My first dive with one had me off-balance. Took a couple dives to get good trim back.

So, Like Rick said.... if you have enough weight on your belt, then I don't see a problem diving steels while wet. I think that problem occurs when people in warmer climates who are only wearing 6lbs or so, try and dive steels.

If you can deflate your bc and swim it up, then you are all set.

 

[Lost Yooper]

Double steel tanks with a wetsuit can lead to problems, but not a single (with a thick wetsuit).

Mike

 

[Mouth Breather old]

Rick Murchison once bubbled...
The difference in a PST LP 95 and a standard AL 80 is 12 pounds in buoyancy. If you're carrying more than 12 with your AL 80 you'll still have ditchable weight with your '95.
I suspect you are, and so I expect you'll be just fine.
Rick

Thanks for replying Rick...so if the above is true for a Faber LP 95 can I go bigger still? Like to a LP Steel 104 PST?

Thanks

 

[Spectre]

Mouth Breather once bubbled...
Thanks for replying Rick...so if the above is true for a Faber LP 95 can I go bigger still? Like to a LP Steel 104 PST?

It really depends on how much weight you're diving with currently, and how much experience you have [to know if you will be dropping weight as you get more experience].

However to look at real numbers: Catalina AL 80 is +4.1 lbs when empty. A PST 95 is -3.3 lbs empty [so 7.4 lbs more negative]. A Faber LP 95 is -1.2 lbs empty [so 5.3 lbs more negative].

PST 104 is the same bouyancy empty as the PST 95. However don't forget about actual surface weight... as that can become an issue as you try lugging these tanks around with all your weight. A Faber 95'll be 37.2 lbs empty, where the PST 95 is 43.8 and the 104 is 46.4 lbs empty.

 

[Goldminer]

Rick Murchison once bubbled...
The difference in a PST LP 95 and a standard AL 80 is 12 pounds in buoyancy. If you're carrying more than 12 with your AL 80 you'll still have ditchable weight with your '95.
I suspect you are, and so I expect you'll be just fine.
Rick

Uh, actually the difference in buoyancy is about 5 lbs when empty. I think you mean difference in empty weight at surface.

According to the manufacturer's websites a PST LP 95 is -1 lb buoyant when empty. A Luxfer S080 is +4.4 lbs buoyant when empty (salt water). A Catalina S80 is +4.0 lbs buoyant when empty. Difference about 5 lbs.


A PST LP 95 is 42 lbs. A Luxfer S080 weighs 31.3 lbs empty. A Catalina S80 weighs 31.6 lbs empty. Difference about 11 lbs. Each full of air the difference would be about 12 lbs.

Remember though that you can take 5lbs off your belt with an LP 95 so the real weight difference is about 6 lbs.

As for whether a steel LP 95 is too heavy to dive wet, well I'm not an expert but, I have heard that this applies to twin sets in warm water where little environmental protection is worn (too much non-ditchable weight to swim too surface vs little buoyancy). I dive a single PST LP 95 wet with a 7 mm steamer suit (sometimes with a vest over it). It works just fine. I have the same problem as you as I am a very big guy and go through air faster than many others do. Most of my friends dive Al 80's.

 

[Scubaroo]

Direct answer:

I'm 6'3", 220lb, wearing a 7mm suit with SS backplate and 10lb ditchable weight. I use a 95 LP that's -10lb at the start of the dive - it's not too heavy to swim up full.