Deploying SMB
- Thread starter MGW1979
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hobodiver
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Does anyone else see something wrong with this?
"Lastly, SMBs should provide enough lift such that divers cannot easily pull it back down to depth. Generally 25 lbs or more of lift is plenty."
"8.) Holding the SMB and spool with the left hand, inflate the SMB till about half full."
Inflating an SMB w/25lbs of lift until it's half full will cause one to have 12 lbs of +ve buoyancy.
For enjoyment only.
Å°n Lift Bag Deployment
An article from Jim Driggers
I recently had my first experience deploying a lift bag. In theintroductory technical diving class, Dennis explained the process clearly: (1) Attach the lift bag to the reel. (2) Put a little air in the bag so itÃÔ easier to prepare to launch. (3) When ready, quickly fill the bag with a good burst from your regulator. (4) Let it go. Pretty simple, huh. LetÃÔ look at that process a little closer. While surrounded by cold water and wearing your sensory deprivation protective gear (SDPG), otherwise known as thick neoprene gloves, feel around your BCD until you find the clip thatÃÔ keeping your reel attached. With SDPG-encased thumb and fingers, unclip the reel. Watch your buoyancy to make sure youÃÓe staying neutral in the water column. With the same SDPGencased thumb and fingers (or with your other handÍØhich is probably also SDPG-encased), find your lift bag and detach it from your BDC. Descend a little because youÃ×e ascended 10 feet while concentrating on detaching two pieces of strange equipment from D rings only recently discovered and not yet reliably located on your BCD. Inflate your BCD because when you realized how quickly you were ascending, you dumped too much air and the extra 100 pounds of technical gear youÃÓe wearing are threatening to sink you like a torpedoed dinghy. Now that the reel and lift bag are detached and youÃÓe stable in the water column, take your regulator out of your mouth. Oh wait, you better attach the lift bag to the reel. Put your regulator back in your mouth and while continuing to use your SDPGencased thumb and fingers, attach the lift bag clip to the loop in the end of the line. Okay, now while juggling the lift bag and reel and staying neutral in the water and trying to remain calm, take your regulator out of your mouth. Put the regulator under the lift bag and quickly press and release the purge valve to partially inflate the lift bag. Now even faster, tip over the top of the lift bag because youÃ×e discharged too much air into the bag and itÃÔ beginning to give you an express ride to the surface. Now dump more air from your BCD because youÃ×e ascended 20 feet in the excitement of trying to control the lift bag and the BCD has taken over elevator duties. Swim back down to the depth at which you want to launch the lift bag. Re-inflate your BCD to establish neutral buoyancy again because, you guessed it, you dumped too much air in your haste to avoid breaking the surface. Now carefully repeat the process of getting the lift bag prepped for launch, except this time press and release the purge valve much faster. Good, youÃ×e got a little bit of air at the top of the bag so itÃÔ properly pointing at the surface and not floating sideways like a limp lasagna noodle. Reel in a little line to make sure it doesnÃÕ snatch an arm or snorkel on its way to the surface trailing behind the rocketing bag. Pull out a little line to make sure the spool is loose enough to not yank the reel out of your hand. Look up to make sure thereÃÔ not someone or something about to be impaled by a submarine-fired missile disguised as a diverÃÔ lift bag. Hitting someone or something that way can make you the target of several return-fire-after-dive jokes. Once the launch trajectory to the surface is clear, take the regulator out of your mouth and again reposition it under the lift bag. Jam the firing button, uh purge valve, and keep blasting air into the bag. Just as you begin to feel it threatening to catapult you to the surface, let the bag go. Keep fingers away from the reel crank, but hold the reel tight as the spool spins up to 3000 rpm. When the spool stops spinning, reel in the 100 yards of extra line it shot out because the line tension was too loose and the spool didnÃÕ stop when the lift bag porpoised out of the water like a water park dolphin touching nose to target 20 feet above the water. Congratulations, youÃ×e launched a lift bag. Hopefully it stayed on the surface and didnÃÕ flop over, deflate itself, and drop like a 500-pound anchor dragging you to the dark depths of MonasteryÃÔ foolish diver exhibit. Was my first try like this? No. I wish it went as smoothly.
Å°n Lift Bag Deployment
An article from Jim Driggers
I recently had my first experience deploying a lift bag. In theintroductory technical diving class, Dennis explained the process clearly: (1) Attach the lift bag to the reel. (2) Put a little air in the bag so itÃÔ easier to prepare to launch. (3) When ready, quickly fill the bag with a good burst from your regulator. (4) Let it go. Pretty simple, huh. LetÃÔ look at that process a little closer. While surrounded by cold water and wearing your sensory deprivation protective gear (SDPG), otherwise known as thick neoprene gloves, feel around your BCD until you find the clip thatÃÔ keeping your reel attached. With SDPG-encased thumb and fingers, unclip the reel. Watch your buoyancy to make sure youÃÓe staying neutral in the water column. With the same SDPGencased thumb and fingers (or with your other handÍØhich is probably also SDPG-encased), find your lift bag and detach it from your BDC. Descend a little because youÃ×e ascended 10 feet while concentrating on detaching two pieces of strange equipment from D rings only recently discovered and not yet reliably located on your BCD. Inflate your BCD because when you realized how quickly you were ascending, you dumped too much air and the extra 100 pounds of technical gear youÃÓe wearing are threatening to sink you like a torpedoed dinghy. Now that the reel and lift bag are detached and youÃÓe stable in the water column, take your regulator out of your mouth. Oh wait, you better attach the lift bag to the reel. Put your regulator back in your mouth and while continuing to use your SDPGencased thumb and fingers, attach the lift bag clip to the loop in the end of the line. Okay, now while juggling the lift bag and reel and staying neutral in the water and trying to remain calm, take your regulator out of your mouth. Put the regulator under the lift bag and quickly press and release the purge valve to partially inflate the lift bag. Now even faster, tip over the top of the lift bag because youÃ×e discharged too much air into the bag and itÃÔ beginning to give you an express ride to the surface. Now dump more air from your BCD because youÃ×e ascended 20 feet in the excitement of trying to control the lift bag and the BCD has taken over elevator duties. Swim back down to the depth at which you want to launch the lift bag. Re-inflate your BCD to establish neutral buoyancy again because, you guessed it, you dumped too much air in your haste to avoid breaking the surface. Now carefully repeat the process of getting the lift bag prepped for launch, except this time press and release the purge valve much faster. Good, youÃ×e got a little bit of air at the top of the bag so itÃÔ properly pointing at the surface and not floating sideways like a limp lasagna noodle. Reel in a little line to make sure it doesnÃÕ snatch an arm or snorkel on its way to the surface trailing behind the rocketing bag. Pull out a little line to make sure the spool is loose enough to not yank the reel out of your hand. Look up to make sure thereÃÔ not someone or something about to be impaled by a submarine-fired missile disguised as a diverÃÔ lift bag. Hitting someone or something that way can make you the target of several return-fire-after-dive jokes. Once the launch trajectory to the surface is clear, take the regulator out of your mouth and again reposition it under the lift bag. Jam the firing button, uh purge valve, and keep blasting air into the bag. Just as you begin to feel it threatening to catapult you to the surface, let the bag go. Keep fingers away from the reel crank, but hold the reel tight as the spool spins up to 3000 rpm. When the spool stops spinning, reel in the 100 yards of extra line it shot out because the line tension was too loose and the spool didnÃÕ stop when the lift bag porpoised out of the water like a water park dolphin touching nose to target 20 feet above the water. Congratulations, youÃ×e launched a lift bag. Hopefully it stayed on the surface and didnÃÕ flop over, deflate itself, and drop like a 500-pound anchor dragging you to the dark depths of MonasteryÃÔ foolish diver exhibit. Was my first try like this? No. I wish it went as smoothly.
There are definitely some techniques involved with safe deployment of a SMB; look at all the nifty knot-work in the videos.
After one hang-up/ butt dragged off the bottom incident, I have since found a method that works for me. I deploy my SMB from 40-50' depending on current, using a 90' reel. Practice and be careful not to get tangled up.
After one hang-up/ butt dragged off the bottom incident, I have since found a method that works for me. I deploy my SMB from 40-50' depending on current, using a 90' reel. Practice and be careful not to get tangled up.
If you fill it half up at any decent depth, it'll be FULL when it hits the surface. Boyles law and all that.
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Gas expands as it goes up. Therefore increases lift capacity of the SMB when it reaches the surface.
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