Balanced rig: Neutral buoyancy limits with no bcd and related safety considerations. Curious what comfort limits others have who regularly dive without a bcd have and what gear configurations work well.
Sharing my observations from a test dive, not suggesting it should be emulated.
Short version: Balenced rig, Two al80s, 2/3mm wetsuit using only lung volume for buoyancy compensation. Comfortable at 65ft. Deco stop at 10' with 500psi also comfortable. Able to hold motionless neutral without uncomfortable breathing patterns or finning.
Longer version:
Remembering the streamlining and comfort of diving without a bcd combined with my newer found love for maintaining the ability to hang motionless without constant finning or fanning I explored the edges of comfort to see how my rig would behave practically without an external bcd, all following bottom contours keeping a hard bottom below me. Outlined is the data and observations.
Relevant equipment: configuration:
Al80s filled to 3100psi
2/3mm full wetsuit size large, slim. I'm 6'2" 175lbs. (Suit closer to 1.5/2.5mm now due to use)
3mm booties (Newish)
Reduced my carried lead by 4lbs.
Dive profile, gas (SM independent doubles pressures rounded and reported as single manifold doubles pressures) and notes:
15ft, 3100psi. Comfortable respiration. Neutral without thought.
50ft, 2800psi. Deeper inhalation needed and breathing from the 'top part' of my full lung begins to be conscious.
65ft. 2800psi. Needing to breathe with lungs predominantly full (comfortable) to maintain neutral buoyancy. I drift for photography 6 minutes while breathing pattern becomes less intentional.
100ft, 2700psi. Can hover without feeling uncomfortably full but in exhalation there's a significant buoyancy change and uncomfortable to breathe at that rhythm.
130, 2700psi. Neutral still possible without packing inhalation but rapid drop when exhaling to breathe. The skip breath pattern of breath is unnatural and narcosis from suspected co2 is predominant.
145ft, 2600psi. Neutral with full feeling lungs. (not packing like freediving, just deep inhalation) finning needed on exhalation. Narced, needing to be negatively buoyant with occasionally finning to hold my place in the water column.
160ft, 2500psi. Narced, can't hold neutral buoyancy without forming the co2 headache and packing my lungs to somewhat uncomfortably full. Task loading for manual dual strobe photography notably challenging and most of my focus needed for maintaining depth and monitoring pressure. Accepting I'm negative and adopting out of trim finning to keep up for cruising. Neutral only for framing photos. Heading up to deco now.
30ft, 1200psi. Notice I'm breathing "normally" neutral buoyancy effortless and familiar. Eagle rays show up to soar and bank with me a while.
15ft, 800psi. Now needing to breathe shallower. Conscious I'm a little light but still within normal comfort.
15ft, 500psi. Breathing shallower, altered breathing pattern. Still neutral comfortably. I clear deco (plus 30 minutes for conservatism and photography) and free-flow the tanks down to near empty in shallow water.
10ft, 200psi. Neutral 1/4 exhaled. Comfortable inhale puts me positively buoyant. Light finning down to be happy.
Slow ascent to surface. Able to bob about comfortably with my head above water on a full breathe.
To those of you who made it through this reflective rambling piece, thanks for your attention.
Discussion welcome.
Regards,
Cameron
Sharing my observations from a test dive, not suggesting it should be emulated.
Short version: Balenced rig, Two al80s, 2/3mm wetsuit using only lung volume for buoyancy compensation. Comfortable at 65ft. Deco stop at 10' with 500psi also comfortable. Able to hold motionless neutral without uncomfortable breathing patterns or finning.
Longer version:
Remembering the streamlining and comfort of diving without a bcd combined with my newer found love for maintaining the ability to hang motionless without constant finning or fanning I explored the edges of comfort to see how my rig would behave practically without an external bcd, all following bottom contours keeping a hard bottom below me. Outlined is the data and observations.
Relevant equipment: configuration:
Al80s filled to 3100psi
2/3mm full wetsuit size large, slim. I'm 6'2" 175lbs. (Suit closer to 1.5/2.5mm now due to use)
3mm booties (Newish)
Reduced my carried lead by 4lbs.
Dive profile, gas (SM independent doubles pressures rounded and reported as single manifold doubles pressures) and notes:
15ft, 3100psi. Comfortable respiration. Neutral without thought.
50ft, 2800psi. Deeper inhalation needed and breathing from the 'top part' of my full lung begins to be conscious.
65ft. 2800psi. Needing to breathe with lungs predominantly full (comfortable) to maintain neutral buoyancy. I drift for photography 6 minutes while breathing pattern becomes less intentional.
100ft, 2700psi. Can hover without feeling uncomfortably full but in exhalation there's a significant buoyancy change and uncomfortable to breathe at that rhythm.
130, 2700psi. Neutral still possible without packing inhalation but rapid drop when exhaling to breathe. The skip breath pattern of breath is unnatural and narcosis from suspected co2 is predominant.
145ft, 2600psi. Neutral with full feeling lungs. (not packing like freediving, just deep inhalation) finning needed on exhalation. Narced, needing to be negatively buoyant with occasionally finning to hold my place in the water column.
160ft, 2500psi. Narced, can't hold neutral buoyancy without forming the co2 headache and packing my lungs to somewhat uncomfortably full. Task loading for manual dual strobe photography notably challenging and most of my focus needed for maintaining depth and monitoring pressure. Accepting I'm negative and adopting out of trim finning to keep up for cruising. Neutral only for framing photos. Heading up to deco now.
30ft, 1200psi. Notice I'm breathing "normally" neutral buoyancy effortless and familiar. Eagle rays show up to soar and bank with me a while.
15ft, 800psi. Now needing to breathe shallower. Conscious I'm a little light but still within normal comfort.
15ft, 500psi. Breathing shallower, altered breathing pattern. Still neutral comfortably. I clear deco (plus 30 minutes for conservatism and photography) and free-flow the tanks down to near empty in shallow water.
10ft, 200psi. Neutral 1/4 exhaled. Comfortable inhale puts me positively buoyant. Light finning down to be happy.
Slow ascent to surface. Able to bob about comfortably with my head above water on a full breathe.
To those of you who made it through this reflective rambling piece, thanks for your attention.
Discussion welcome.
Regards,
Cameron
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