OP
Streamlining my gear
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Now I see what you're talking about, with all that dangling crap in the pictures. Do you know how much drag a reel creates? That dangling light? It's a wonder you're able to get any bottom time at all dragging all that stuff through the water.
Foxfish
Contributor
Attach one end of string to the diver and the other to a spring scale. Tow diver in a pool at a constant speed to measure resistance. (Engineer's solution)
If things stick out, try to tuck them in. Just needs a bit of common sense. Speed and drag is not a big deal when scuba diving. Most dives you travel a few hundred metres. I also freedive and that is a different story. You can fin a few kilometres in a big day of diving and streamlining can make a big difference.
LOL, Mossman!
BTW, the tank pictured is a PST steel 72 (71.2 cu ft @ 2,475 psig) which is 25" tall (with a 6.9" diameter). I actually prefer to dive this SSJ setup using a Sherwood Genesis 80 (i.e., a PST HP 80; 82 cu ft @ 3,500 psig) which is only 20" tall (with a 7.25" diameter)--an even smaller package!
When I dive dry or a thick wet suit, I thread a 4# or 5# solid weight onto the SSJ's tank strap and increase my weight belt by the additional required weight.
Ronald
I have found that streamlining is helpful but I don't think we would agree upon what is streamlined and what is not.
It is easy to test your gear for streamlining. Swim it in a pool over a distance, then do the same with the supposed streamlined configuration. Do this several times over several days or weeks, do one first and then the other and then average. No, it will not be super accurate but you will see differences. Gauge your workout rate by your heart rate just like runners and swimmers and cyclist do. This confirms a relatively equal power output. Also, notice your distance vs psi consumed! Use the same fins.
To make this work, you have to put some effort into it, no put, put, putting along like a slug, put your fins in high gear and go!!!!!!! Get the heart rate up, around 110-120 for me works well. Test over about .25 miles. Oh, and do the swim submerged.
I have done this, more than once with multiple types of gear set ups and I will not bias your results by telling you mine but I can see big differences in gear configuration.
N
It is easy to test your gear for streamlining. Swim it in a pool over a distance, then do the same with the supposed streamlined configuration. Do this several times over several days or weeks, do one first and then the other and then average. No, it will not be super accurate but you will see differences. Gauge your workout rate by your heart rate just like runners and swimmers and cyclist do. This confirms a relatively equal power output. Also, notice your distance vs psi consumed! Use the same fins.
To make this work, you have to put some effort into it, no put, put, putting along like a slug, put your fins in high gear and go!!!!!!! Get the heart rate up, around 110-120 for me works well. Test over about .25 miles. Oh, and do the swim submerged.
I have done this, more than once with multiple types of gear set ups and I will not bias your results by telling you mine but I can see big differences in gear configuration.
N
Oh, the Doc, mentioned scootering. Oh, yeah, this will show real quick. I have also run my Teknas with different gear configurations and they mirrored my swim tests, exactly.
N
N
Nemrod,
Between you and me, once my daughters' piano is paid off, if at all possible I will purchase a custom Rubatex G-231-N wetsuit. Then, I hope to dive my SS Freedom Plate and harness, without a BC, with my 72. I suspect I will be extremely streamlined then! (If I'm able to hit the gym/track enough, I might be able to increase my lung capacity enough to use a Worthington HP 100, instead of my 72, for deeper/longer dives.)
But the OP didn't ask about this. He asked how he might streamline his jacket-BCD-based rig.
Safe Diving,
Ronald
Eric Sedletzky
Contributor
These discussions in the past have made me want to run full speed head first into a brick wall out of frustration,
but I'm going to give it a shot anyway.
I've made it my mission in my amature world to really think about this topic and come up with what I think is the most streamlined (there's that word again) way to dive on scuba.
I substitute the word "streamlined" with "slipstream". I have an obsession with trying to remove anything (within reason) that I see as needlessly interfering in a smooth slipstream as your body slides through the water. When ever there is something sticking out it's going to cause water to hang up on it and it will cause drag.
So lets start with what I think is the most cluttered diver you can think of. The the sake of this discussion lets look at a single tank recreational diver.
A diver wearing a big baggy drysuit with huge thigh pockets stuffed full of redundant gear wearing a very large and over padded jacket style bc with integrated weights that are under BC pockets which are also stuffed with gear. The tank sits very far off the divers back because of the design and the regulator has hoses sticking out in all directions. The octo hose sticks out, the console HP hose sticks out and the console is mounted on a retractor that allows the console to hang down a foot or so below the diver. The diver also has a pistol grip light hanging off one of the shoulder D-rings that hangs down plus lets add a slate hanging off the other D-ring dangling around. This diver has about as much stuff as possible sticking out everywhere which interferes with the slipstream.
Now we can begin to remove or change things to improve the slipstream.
If possible, switch to a wetsuit or pick a drysuit that has a body hugging fit with less wrinkles and smaller thigh pockets. Don't stuff everything into the thigh pockets including the kitchen sink, this is only a recreational dive not a dive to the titanic.
Consider switching from a jacket BC to something that doesn't have all the crap on your front side with big integrated weight pockets and big storage pockets. Also the air cells on the sides and front on those things stick out and cause an obstruction. Also, other BC options allow the tank to sit closer to your body which reduces your overall circumference, so the hole you make when you cruise forward through the water is smaller meaning less water having to be pushed out of the way and around you = good.
Re-route hoses so everything is run down from the reg and sits closer to your body. Get rid of the console and use a small SPG clipped off to a D-ring on your waist.
Instead of a large pistol grip light look into a smaller cylindrical light that can be clipped off to your shoulder D-ring and the bottom part bungeed to the shouder strap so it doesn't hang down.
A step further...
This is not for most people and this is where I get in trouble with the industry dive gods that claim I will poison the minds of the young and tender newbie and put people in danger. Oh well...
Going the absolute minimalist method is the most streamlined of any configuration and doesn't really serve any purpose other than for extreme speed, stealth, and in the case of vintage diving to be authentic in dress as they did not have or use BC's back in the day.
Most recreational divers wouldn't have a reason to pick such a configuration, but hunters, lobster divers, and as I said vintage divers tend to gravitate towards different degrees of minimalist diving.
The configuration:
Wetsuit.
Tank mounted on a backplate or plastic back pack with no BC or a tank set up with harness straps only and worn directly on back.
Minimal regulator set up with sometimes only one second stage and an SPG. Sometimes no SPG just a J valve on the tank.
Depth gauge and watch, or modern configurations include wrist computer or bottom timer.
Weightbelt with flat hard weights or a line of one lb. bullet weights.
Weighting must be exact to be able to dive like this.
Finning and body positioning also has a big affect on your slipstream. It seems all the rage these days for all types of diving for people to go around with their feet up bent at the knees 90 degrees and scull their fins in what they call a frog kick (which is actually not a frog kick at all). Bending your knees and having the lower part of your leg sticking up interferes with your slipstream and is not an efficient style of kick because the propultion gained is cancelled by the oncoming water hitting the legs (calf side). I'm not a buyer of the cave diver style fin kick being the one fits all kick for all diving environments.
A faster and more efficient profile is to keep your body straight with your legs straight back. Try a small flutter kick just using your lower legs and feet. The other kick which I find very effective and requiring very little effort is the porpoise kick keeping both fins together and hinging your body at your pelvis and swaying the fins up and down like a dolphin fin with a smooth steady motion. Keep your arms to your sides or out stretched as far as you can reach foreward to maximize your slipstream.
In the end, most people don't really care about things like efficiency, streamlining, slipstream, reducing clutter, etc.
Many divers take pictures and just hang around waiting for the shot or don't mind going at a snails pace and just looking at stuff.
None of it really matters as long as you're having fun, but if you are interested the info's out there.
but I'm going to give it a shot anyway.
I've made it my mission in my amature world to really think about this topic and come up with what I think is the most streamlined (there's that word again) way to dive on scuba.
I substitute the word "streamlined" with "slipstream". I have an obsession with trying to remove anything (within reason) that I see as needlessly interfering in a smooth slipstream as your body slides through the water. When ever there is something sticking out it's going to cause water to hang up on it and it will cause drag.
So lets start with what I think is the most cluttered diver you can think of. The the sake of this discussion lets look at a single tank recreational diver.
A diver wearing a big baggy drysuit with huge thigh pockets stuffed full of redundant gear wearing a very large and over padded jacket style bc with integrated weights that are under BC pockets which are also stuffed with gear. The tank sits very far off the divers back because of the design and the regulator has hoses sticking out in all directions. The octo hose sticks out, the console HP hose sticks out and the console is mounted on a retractor that allows the console to hang down a foot or so below the diver. The diver also has a pistol grip light hanging off one of the shoulder D-rings that hangs down plus lets add a slate hanging off the other D-ring dangling around. This diver has about as much stuff as possible sticking out everywhere which interferes with the slipstream.
Now we can begin to remove or change things to improve the slipstream.
If possible, switch to a wetsuit or pick a drysuit that has a body hugging fit with less wrinkles and smaller thigh pockets. Don't stuff everything into the thigh pockets including the kitchen sink, this is only a recreational dive not a dive to the titanic.
Consider switching from a jacket BC to something that doesn't have all the crap on your front side with big integrated weight pockets and big storage pockets. Also the air cells on the sides and front on those things stick out and cause an obstruction. Also, other BC options allow the tank to sit closer to your body which reduces your overall circumference, so the hole you make when you cruise forward through the water is smaller meaning less water having to be pushed out of the way and around you = good.
Re-route hoses so everything is run down from the reg and sits closer to your body. Get rid of the console and use a small SPG clipped off to a D-ring on your waist.
Instead of a large pistol grip light look into a smaller cylindrical light that can be clipped off to your shoulder D-ring and the bottom part bungeed to the shouder strap so it doesn't hang down.
A step further...
This is not for most people and this is where I get in trouble with the industry dive gods that claim I will poison the minds of the young and tender newbie and put people in danger. Oh well...
Going the absolute minimalist method is the most streamlined of any configuration and doesn't really serve any purpose other than for extreme speed, stealth, and in the case of vintage diving to be authentic in dress as they did not have or use BC's back in the day.
Most recreational divers wouldn't have a reason to pick such a configuration, but hunters, lobster divers, and as I said vintage divers tend to gravitate towards different degrees of minimalist diving.
The configuration:
Wetsuit.
Tank mounted on a backplate or plastic back pack with no BC or a tank set up with harness straps only and worn directly on back.
Minimal regulator set up with sometimes only one second stage and an SPG. Sometimes no SPG just a J valve on the tank.
Depth gauge and watch, or modern configurations include wrist computer or bottom timer.
Weightbelt with flat hard weights or a line of one lb. bullet weights.
Weighting must be exact to be able to dive like this.
Finning and body positioning also has a big affect on your slipstream. It seems all the rage these days for all types of diving for people to go around with their feet up bent at the knees 90 degrees and scull their fins in what they call a frog kick (which is actually not a frog kick at all). Bending your knees and having the lower part of your leg sticking up interferes with your slipstream and is not an efficient style of kick because the propultion gained is cancelled by the oncoming water hitting the legs (calf side). I'm not a buyer of the cave diver style fin kick being the one fits all kick for all diving environments.
A faster and more efficient profile is to keep your body straight with your legs straight back. Try a small flutter kick just using your lower legs and feet. The other kick which I find very effective and requiring very little effort is the porpoise kick keeping both fins together and hinging your body at your pelvis and swaying the fins up and down like a dolphin fin with a smooth steady motion. Keep your arms to your sides or out stretched as far as you can reach foreward to maximize your slipstream.
In the end, most people don't really care about things like efficiency, streamlining, slipstream, reducing clutter, etc.
Many divers take pictures and just hang around waiting for the shot or don't mind going at a snails pace and just looking at stuff.
None of it really matters as long as you're having fun, but if you are interested the info's out there.
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