Diving without BCD?

[tech_diver]

Nobody's mentioned 'monkey diving' yet....

But it's for advanced divers...

 

[DanSinks]

It is difficult to give someone advise about if they should try diving without a BCD without knowing the person.
How competent is that person in general, are they normally able to work around problems?
If you are going to do this, then plan your first dive. If it's to be from shore is it an easy entry without a crashing surf?
Is it sand or rocks?
There are a lot of details that need to be handled. The devil is in the detail.

 

[Scuba Lawyer]

Thanks, that's helpful! I guess it's a combination of limiting depth (and therefore exposure suit compression), not having a safety stop (so no need to be completely neutral at 15 feet), and better breathing compensation (more time with fuller lungs). I'm sure that like any other skill, it gets better with practice.

Just wanted to point out one common misconception. You said: "For me, aluminium tanks (and some steel tanks) have too much of a bouyancy swing."

Apart from suit compression, the only thing that changes during a dive is the gas that you consume, so the difference in the buoyancy is just that - the weight of that gas. Whether you dive with steel double 119s or a single fiberglass 3 liter tank, the buoyancy swing is the same. Your total ballast needed to stay at depth is what it is. Whether that ballast is from a steel backplate, a tank, ditchable pouches, trim weights, a weight belt or anything else just determines how that ballast is distributed. If you are diving in a bathing suit only and are overweighted with a steel tank and no additional weight, then you need a less negative tank. But buoyancy swing is not related to tank composition.

Interesting. Again, I ain't no physics guru and can only opine from my own experience. For example, I did a no BC dive using an AL80 a few years ago off a friends boat. I weighted for basically being neutral at 10-15 feet (as usual and as I do with my steel 71.2's which are neutral at the end of the dive). At the end of the dive I was slightly more buoyant than usual during my last 10-15 feet. I estimated maybe 2 or 3 pounds more buoyant. I was told (by no one with any credentials to speak of) that AL tanks have a buoyancy swing from a few pounds negative at the start of the dive to a few pounds buoyant at the end of the dive as the weight of the air consumed. In other words, you are ending the dive with some buoyancy in the tank. Now, I did use a few pounds more weight with the AL80 than with my steel 71.2 so it seems like you are correct that the net buoyancy swing is just the weight of the gas. Even though the AL tank was a few pounds more buoyant at the end of the dive, my extra few pounds of weight should have offset that increased buoyancy. Why then did I seem light at the end of the dive, all else being equal? I may have been diving for a long time but the more I think about things the less I realize I know. Anyway, that one experience was the basis of my (apparently erroneous) statement. I stand corrected. M

 

[doctormike]

Interesting. Again, I ain't no physics guru and can only opine from my own experience. For example, I did a no BC dive using an AL80 a few years ago off a friends boat. I weighted for basically being neutral at 10-15 feet (as usual and as I do with my steel 71.2's which are neutral at the end of the dive). At the end of the dive I was slightly more buoyant than usual during my last 10-15 feet. I estimated maybe 2 or 3 pounds more buoyant. I was told (by no one with any credentials to speak of) that AL tanks have a buoyancy swing from a few pounds negative at the start of the dive to a few pounds buoyant at the end of the dive as the weight of the air consumed. In other words, you are ending the dive with some buoyancy in the tank. Now, I did use a few pounds more weight with the AL80 than with my steel 71.2 so it seems like you are correct that the net buoyancy swing is just the weight of the gas. Even though the AL tank was a few pounds more buoyant at the end of the dive, my extra few pounds of weight should have offset that increased buoyancy. Why then did I seem light at the end of the dive, all else being equal? I may have been diving for a long time but the more I think about things the less I realize I know. Anyway, that one experience was the basis of my (apparently erroneous) statement. I stand corrected. M

Yes, when we are talking about buoyancy swing, we mean the change in overall buoyancy of the whole system from the beginning to the end of the dive. The system is your body, your exposure suit, your rig, and whatever else you are carrying with you. So (again, leaving out the exposure suit which loses and then gains back buoyancy over the course of the dive), the only thing that changes is the fact that you are carrying about 5 lbs less gas at the end of the dive. That's the buoyancy swing.

If you are weighted so as to be perfectly neutral at 15 feet at the beginning of the dive, you will be 5 lbs buoyant at the end. If you are perfectly neutral at the end of the dive (currently recommended), you will be 5 lbs heavy at the beginning (which is what the buoyancy compensator is compensating for, along with suit compression).

So to answer your question, if you feel light at the end of the dive, that means that you are underweighted, and need to carry more ballast. You don't want an uncontrolled ascent at the end, so that's why some people err on the side of slight overweighting and compensate with the BC. But of course, getting back to the OP, even if you don't need a BC for diving, it's a good safety feature for a 65 year old without a lot of recent diving experience on the surface.

 

[Scuba Lawyer]

So to answer your question, if you feel light at the end of the dive, that means that you are underweighted, and need to carry more ballast. You don't want an uncontrolled ascent at the end, so that's why some people err on the side of slight overweighting and compensate with the BC. But of course, getting back to the OP, even if you don't need a BC for diving, it's a good safety feature for a 65 year old without a lot of recent diving experience on the surface.

What's funny is that I've always known that but it's not something I've thought about in a long long time. Pretty basic stuff really. Agree that a BC is the best choice for most divers. M

 

[Sam Miller III]

1. FYI: from my files..
2. The oldest dive documented dive on the SCUBA Board -1960 --59 years ago-

1. The very first recreational SCUBA dive at the famous and never dove Farnsworth banks off Catalina Island -- worth a read as "the way it was "
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   "I was the President of the Sea Sabres dive club in 1959-60. The previous President Bob Ruethford, who had founded the Aquatic Center in Newport Beach, had seen hunks of purple coral (allopura California) brought in by commercial abalone divers. Over a few drinks Bob discovered they found it at a place called Farnsworth banks. Selected member of the Sea Sabres and the scientific community at Kirkoff marine institute in Corona Del Mar consequently made a number of trips to the banks on the private boat called the "Aqua Duck."
   
   Bob, a true diving pioneer who is famous for many first in diving (see www.legendsof diving: Sea sabres signaling system) who relished publicity,published an article in Skin Diver magazine in June 1960 "California divers discover Rare purple coral' which was fine but his topside pictures clearly showed Ben Weston Point in the background. That same month Jake Jacobs the then head diver at Marine Land of the Pacific published "Marine land diver" (--Dodd, Meade & company NYC, LCC 60-9655 --I have an inscribed copy) in which Jake also discusses the purple coral of Farnsworth -- So the secret of Farnsworth was out.
   
   As the president of the then undisputed most active dive club in all of SoCal and possibly the US I made the decision to dive " Farnsworth banks". I contacted the dive boat captains at that time, all refused to charter to Farnsworth as if it was some foreign or strange exotic place. Finally Dick Peters, who owned the newest dive charter boat of the fleet, the 42 foot "Out Rider " agreed to a charter at $7.00 per person but with the stipulation "only in the winter when there are no boats fishing there and the water will be calm" (FYI the Outrider sunk about 1967 when returning from a trip to Catalina)
   
   In early December 1960 we loaded the boat. It had no compressor - as many as three- four or even five tanks per person was stashed all over the boat. The water was like glass and the trip over and back was like riding on silk.
   
   Using Ben Weston Point as a reference and relying on the recently developed depth finder Captain Peters made numerous runs in all directions across the banks trying to locate a pinnacle.
   
   Finally a suitable pinnacle was located and the anchor was dropped in abut 100 feet of water --right in the middle of a school of hungry welcoming sharks. "The are only blues, lets dive! " some one shouted. With only a nano second of hesitation on that bright sunny day in December 1960, Ed Mossbrooke (who now lives in Fountain Valley) became the first recreational diver to dive the Banks from a charter boat, immediately followed by the rest of the divers.
   I was using the then very popular "Orange County twin 44s." Harry Vetter (LA CO UW Instr & NAUI #4 )was using surplus USN single aluminum 90s, the others were using every thing from a single 70 to twin 72s. All breathed from a variety of double hose regulators, most used the recently introduced wet suits which were home made, although the SPG had been introduced in 1954 it was considered unreliable and was seldom used, and of course floatation devices were still fifteen years in the future. At that time we were diving with the state of the art equipment but today we would be considered "antique, retro or old school."
   
   It was a different world at that time with no thought for the future or the conservation of the precious natural resources. We came for hunks of the famous purple coral of Farnsworth banks and we harvested hunks of purple coral. In addition most harvested a limit of ten scallops, and the then limit of ten bugs, with Harry Vetter getting the largest at 13+ pounds.
2. 
   I some how in my four dives that day managed also to spear a rather "large fish," which because we were not equipped for large fish took some doing to horse it on the boat.
   
   All too soon it was all over, the divers began returning to the Outrider, storing their equipment, game and hunks of purple coral. All that is but, Norma lee Smith who decided to decompress on the bow line and attracted every curious and hopefully not hungry shark from miles around investigate this morsel. Norma's only defense was to exhale copious amount of rapidly diminishing supply of air. She slowly with great caution made her way to the stern of the boat where she rapidly ascended thrust out her hands and was unceremoniously but also rapidly pulled over the gunnel onto the deck of the Outrider...So ended the first recreational dive trip to Farnsworth.
   
   So many adventures, so many stories...(and most of us were from OC...)
   
   Dr. Samuel Miller,
   LA Co UW instructor-11
   NAUI instructor # 27
   PADI et all was ten years I the future

 

[Sam Miller III]

1. "The first dive revisited-- continuation -- Part 11
   Farnsworth banks is a bank aka reef on the back side of Catalina Island, in the open ocean it is deep, cold and in the 1950s it was full sharks wanting a hand out from the fishing boats that often visted the banks. It was first dove in early 1950s by a hement diver which was aborted, then again in late 1950s which was also aborted due to currents. I went on several "exploratory SCUBA dives" with Sea Sabre Club President Bob Retherford (see Legends of Diving sea Sabre Sigaling System) and several members of the scientic community in 1959 -1960-
   
   On occasion I exchange e mails with those remaining from the 1950 & 1960s dive tribe. Ed Mossbrooke was the very first recreational diver to dive Farnsworth in December 1960. What follows is extracted from an E mail from Mossbrook--the first recreational diver to dive "The Banks" I hope you you enjoy this exchange - an account of the first dive recreational dive on Fransworth banks
   
   Ed's e mail:
   
   "You forgot about my excitement about being the first to dive on the Banks.
   
   As you recall I was the only one who had the newly introduced oil filled navy depth gauge, most of the rest were using capillary or bordan tube or no gauges and I was also the only one diving twin 72s. Therefore I was "volunteered" or was it "selected?" to be the first to dive and check out the diving location called Farnsworth.
   
   I was standing on the swim step of the Outrider I was just about to enter the water when Norma Smith asked if I planned to put on my fins! In my excitement I had failed to put on my ducks. (ed note a fin==Duck Feet) It would have been a total disaster since we were all diving with out flotation and I would have sunk right to the bottom.
   
   I entered the water and was well into my first dive and had leveled off at 180 feet when I noticed the strong current was suddenly caring me upwards right and into the peak of the pinnacle around 100 feet. Low and behold had a metal box with small railroad wheels and short cable which had a ball with spikes sticking out of it. Another derelict WW11 mine! But different than the others we had seen at Scotsmans cove and Catalina. ( common occurrence after WW11 on the coast ) At that moment I did an explosive decompression ascent (all most) and yelled to "Dick There is a mine on the peak of the reef!" Dick Petter replied "Not to worry as the local notice to mariners had a notice about the instrumented mine that was placed there to monitor currents and sea temperatures." The Sea Sabers on board had a hell of a laugh about this. The event would not have been as funny if he told me before I entered the water.
   
   What about your over sized lift bag to bring up a vast amount of purple coral? WW11 surplus of course as most of our equipment was at that time (A surplus 55 gallon Lister bag aka drinking water bag). Recall we filled a big box with coral and you filled the lift bag from your mouth piece with air. It immediately began its journey to the surface to picking up speed as the air filled the body of the lift bag When the box hit the surface it sort of launched like a Polaris missile fired from a sub. I can still remember the raining down of Purple coral to the bottom and I only had enough air left to grab 1 of purple coral and start my assent.
   
   Or Sheila Platt who was diving with Harry Vetter asked Harry before beginning their descent "How deep are we gong? replied Harry replied "To the bottom." And they did reach the bottom. Down the dove. 90, 100, 120 140, Sheila's depth gauge was only rated to 140, but ever deeper they sunk until the sand was reached at an estimated 240 feet. Between dives Sheila displayed her new Borden tube depth gauge, suck at 140 feet and full of water.
   
   Or when you were followed to the boat by a rather substantial hammerhead. You were totally oblivious to it's presence. You just slowly took your time snorkeling back unaware that a large shark was interested in you as lunch. That is until you reached the swim-step and noticed that Dick Petter had his rifle pointed at you all the divers were congregated at the swim step with hands outstretched to yank you into the boat.
   
   It was Sheila who later broke the tension when she said "Sam I was watching you play tag with that shark when I was eating a chicken for lunch --bones and all"
   
   What adventures we had on every dive -
   
2. Ed Mosbrook"
   
   
   ***** note;
   All the dives were made using "double hose regulators" Duck feet or Churchill fins and very crude often homemade equipment; masks,(Harry Vetter & I were using Sturgil homemade Masks- Legends of diving "The Mask" & Bio of Harry Vetter ) wet suits (introduced in 1954 were home made from WW11 surplus rubbber sheeting $1.00 at Kirkhoff Rubber Co in Brea California ,) lift bags (were converted WW11 Surplus items ), we dove devoid of modern instrumentation, a few effective depth gauges, no SPGs, no thermometers, no back plates ( back packs)!
3. 
   
4. Only Fins Mask & snorkel wet suit and weight belt
   
   Most of the divers on that first dive on Farnsworth in December 1960 are now diving in the big reef in the sky. Only a few remain and we remain in occasional contact
   
   Sheila Platt, was the Office manager of Skin Diver magazine, always had a way with words. She had the honor of the first woman to dive to the bottom of Farnsworth on air according to Dick Petter 240 feet, but also was the first to reach that big reef in the sky about 2 years later from cancer
   
   Harry Vetter is a spry 89 retired in NW and is the oldest living NAUI instructor with the lowest number - NAUI - I am the third or forth oldest living member of NAUI
   
   Those were -- "The days of our dives..." experienced by a preciously few which will never ever be repeated again in the modern diving world

Sam Miller, III

 

[W W Meixner]

Hey all,

Can you dive without a BC - is it OK/do-able or is it suicide?

I guess this is mostly for the guys who've been diving since the 70s (if they're on the interwebs?). As a bit of background, I'm 40, and just got into diving. I've always loved it but was unable (certified) until now due to previous medical condition. My father is 65, and has not dove for a long time, but wants to get back into it with me. I would love that to happen but funds are very limited for both of us.

He has some vintage gear that could be serviced OK - Conshelf XI and Calipso ?? regs. Tanks are out of spec (all gear is circa 1970s) but not too much to hire.

He doesn't have a BC. He never has - I don't believe they were invented back then. He just has a bracket with straps that holds the tank to your back. As far as he's concerned it's all he needs and all he uses. But I'm a little nervous of diving with him if there's no way to get him to the surface. So is it a really bad idea, or is it OK?

(For context, my dad also reckons the dive is over when you can't suck air any more LOL).

Thanks!

Todd...

There's lots of long answers...especially from the Sea Hunt/buggy whip crowd...your short answer is you shouldn't...

Take the training...buy the correct pieces...either new or used...of which there is lots of...and do it right...a lot of what your father may have learned back in the day is not considered acceptable practice anymore...he should be re-certified to todays standards...

Your Dad's old regulators may not have enough LP first stage ports for safe seconds and inflator hoses...make sure first before you spend any money getting these old pieces serviced...

If it's cost prohibitive to do it the right way...then forget it...there's absolutely nothing down there worth jeopardizing either you or your fathers safety...

Dive Safe...

Warren

 

[Damselfish]

I agree, do it right. If you can't afford to, don't. Used gear can be a pretty good deal.

You're talking about someone who hasn't dove in a very long time. Without the distraction of the whole diving with no BC discussion, I suspect all you would see is suggestions your dad take a current certification class. Or at the very least a refresher, but I don't know if that will teach all the things he doesn't know about to begin with. Maybe you could find an instructor willing to work with this and do a special sort of refresher, if it's within standards? Tell him it's for you. If you will be diving together you will want to start with a common knowledge base and ways of doing things. If you will have the opportunity go on charter boats, they may have rules that he can't dive without a BC, and maybe other things he doesn't have. (Does he still have a c-card, did he ever?)

I doubt anyone is going to let him do a class in vintage gear. Most cert classes will include at least rental BC & reg anyway, which will give him a chance to try out the new stuff. He may like it. And if he really wants to dive vintage gear again, he can make an informed decision. Maybe you will want to try it out with him. But I think that's for a little later.

 

[Jim Lapenta]

After diving for 15 years and becoming a recreational and technical instructor, I got to dive a vintage Mistral single stage with a steel 72 and backpack with no BC in the pool a few weeks ago.
In my 5 mil with a few pounds of lead to offset the added buoyancy of the suit, I found that maintaining buoyancy was easy. But then I've been preaching proper weighting since I became an instructor in 2008. The only issue I had was I had to doff the bc a couple of times to adjust the tank height and get out of true horizontal trim because the nature of the reg dictates that it needs to be in just the right position and slightly head up to breathe best. Otherwise, I'd have zero issues with diving it at recreational depths.
It's not unlike the free diving class I took last summer. That was an eye-opener in some ways due to the techniques and some other tidbits of info I picked up.
The thing is now that if you are going to get recertified or even do a refresher, many agency standards require a BC to be used. The instructor doesn't have the option to not use it.