Hy-Mark vs Luxfer Buoyancy

[tk trekers]

I hope this is the right forum for this question, I searched and could not find anything about this.

Is there a difference in the buoyancy characteristics between Hy-Mark and Luxfer AL80 tanks?

 

[SparticleBrane]

I have heard (but have no first hand experience) that the Hy-Mark cylinders were designed to be as close to Luxfer as possible, and they seem to have accomplished this.

I've read a few threads on other boards where people took Hy-Mark cylinders and Luxfer cylinders side by side in a pool, same pressures, to see how they sank or floated and what position they took -- apparently they were practically identical.

 

[tk trekers]

Anyone else have any info? The reason I ask is that I dove for the first time in my short wetsuit today and accordingly dropped a couple of pounds of weight since I wasn't in my full wetsuit and used a Luxfer for my first dive, no problems. Second dive I used a Hy-Mark and my buoyancy was erratic, even for me being a newer diver. I was just trying to determine if anyone knew if there was any difference between the manufacturers?

 

[WD8CDH]

I have detailed specs. for both. What tank size?

 

[tk trekers]

Both tanks are 80's.

 

[WD8CDH]

HyMark S-80 7.25" dia, 26.1" long, 31.3 Lb. 684 cu. in. internal volume
Luxfer S080 7.3" dia., 26.1" long, 31.4 Lb. 678 cu. in. internal volume