Buoyancy

Hello Divers!

Recently, a customer stopped in to inquire about purchasing a 120cuft tank for her husband.  She explained that she and her husband were newly certified divers and that her husband consumed his air so much faster than her.  In their travels to area dive shops, they had been advised that he could even up his air time to match hers by getting a bigger tank. While this definitely a solution, it is not the one I would have suggested.

Poor air consumption can be tracked to poor fitness, physical problems or lack of streamlining.  All of these issues need to be addressed to increase a diver’s air time, but once issues are addressed, before I would suggest a bigger tank, I would challenge the diver to address an even bigger cause of poor air consumption: poor buoyancy.

Good buoyancy leads to better air consumption and more comfortable diving.

We’ve all observed this in action; one diver bicycling along in the water and another flailing his arms like a windmill.  Look for these two to be back on the boat long before the rest of the group.  The quickest exercise for a new diver to do that will give immediate feedback as to their buoyancy is to dive in a horizontal position with arms crossed in front.  If the diver cannot maintain his depth in this position, then some adjustment must be made. 

If they are sinking add air.  Wait a bit for the added air to equilibrate to the surrounding temperature, then reposition: horizontal, arms crossed.  Repeat this process until the diver can maintain the desired depth with minimal movement.  Of course, if the diver is too positive, air should be dumped, but remember that it is possible to dump a small amount of air. After venting a small amount of air, the diver should exhale, then reposition, etc. 

I look at things like getting ankle weights if feet are too buoyant or bigger tanks when air consumption is a problem as masks merely covering the underlying problem. Scuba is like any other skill or hobby.  To be good at it, one needs to practice and continuously learn better technique.  Walter Elliott said, “Perseverance is not a long race: it is many short races one after another.” I think this describes the journey that all of us take to good buoyancy.  We persevere though out fin pivots and hovering exercises in class and then, after earning our certification, we continue on that course to perfection. 

If you want a bit of coaching on your buoyancy, we suggest the Peak Perfomance Buoyancy course, or participation in this winter’s buoyancy clinic.  You may also want to check out this month’s Dive Training magazine and read their pointers for good buoyancy.

A Shared Story

I like to share my dive experiences, but I also enjoy passing along stories I hear from other divers.  Ken Welch, someone who was a diver back in the day and who has of late gotten back into the sport, (with remarkable zeal, I might add) shared this experience via e-mail:

Dive Training Magazine states on its cover that “A Diver is Always Learning.”  I had a new experience on my last dive.  I had ascended from diving the bow portion of the Milwaukee Car Ferry. I was performing a safety stop at 15 feet.  There was not much current but a NE wind had increased since we had descended. There was a little pitching on the mooring line.  Unfortunately I was a little positively buoyant so I needed to use the mooring line to assist me in maintaining my depth.  My buddy was also hanging on the line 3’ below me.  All of a sudden upon taking a breath, I had a mouthful of water.  I had a mouthpiece in my mouth and could not immediately figure out what was going on.  I reached up with my right hand and found that there was no second stage attached to my mouthpiece.  I took the mouth piece out and switched to my other regulator. Later that evening I inspected the mouthpiece.  Apparently the cable tie that holds the mouthpiece to the second stage had broken and fallen off.  The mouthpiece still had the impression of the cable tie on its surface.  What is interesting is that this regulator was purchased new in January 2014.  Cable ties used for this application have a breaking strength of at least 50 pounds.  Rather than break I think the cable tie failed at the “tooth” that engages the serrations.  The “tooth” failure may have been assisted by my Miflex second-stage hose rubbing against the “tag” sticking out of the “eye” of the cable tie in the choppy water.  I replaced the cable tie with one obtained from Lowes.  I was unable to reproduce the failure.  I also ordered some Thomas and Betts cable ties that conform to a Mil-Spec.  I suspect that this one of those one in a million types of events, but I have added inspection of the cable tie to my pre-dive inspection.  

Regards, Ken

This experience teaches two lessons. First, when things go pear shaped during a dive, calm heads will prevail.  When faced with a malfunctioning regulator, Ken did what all divers are taught in open water class; Stop, Think and Act.  The first order of business was getting some air.  He switched to his alternate air source. With the immediate issue handled, the dive could continue safely.

Second, Ken investigated the issue and made adjustments to his pre-dive plan and improvements to his equipment to prevent this problem from occurring in future dives.

Yes, a good diver is always learning, from magazine articles, dive instructors, personal experiences and the experiences of others.

Lake Michigan Dive

With the short summers we have here in Wisconsin, everyone does their best to make the most of the season.  We at Manta Divers are no exception.

 On Saturday, 6 lucky Team Manta members joined me on two Lake Michigan dives off the catamaran, Mai Tai. I say the participants were lucky, but perhaps quick is a better descriptor.  This dive outing was booked within a week of being posted on our calendar. We left McKinley Marina in Milwaukee at 8am and headed out to the Prinz Willem and the Dredge, two of the lake’s most popular wrecks. The lake was flat as could be, so the 40 minute cruise to the site was particularly enjoyable. I enjoyed sitting on the bow watching the sun climb in the sky, letting the lake breeze blow my hair.

Though the water was exceptionally flat, exceptional underwater visibility was not a guarantee. However, when we got to “The Willie’s” mooring, it looked quite promising.  We all geared up and entered the water, bracing for those first trickles of frigid Lake Michigan to seep into our suits. (That is to say all of us but the drysuit divers!)   After checking that everyone was squared away, we signaled to start the descent. 

It is imperative in Lake Michigan that divers descend with at least an eye on the mooring line. The thing is that there may be a mild current and even if a diver thinks that he is descending straight down, he may not.  It is exceedingly easy to miss the wreck all together, and not be able to find it at depth.  Therefore, we made our descent along the mooring line and soon were at 70 ft. looking at the stern of the Prinz Willem.  We could see almost to midship from that vantage point, so we all knew we were in for a treat.  We toured around the 258ft ship, now encrusted in mussels and algea. With such great water clarity, divers were better able to get a sense of the majesty of this ill-fated vessel.   As the wetsuiters got cold, and others came to the end of their air, the group ascended and ended the dive.

Photo by Scott Durban

We sat around the charter boat discussing the dive and rehydrating while Captain Rick ferried us to our next site, the Dredge No. 6.  At the Dredge’s mooring, we could see the top of out of the “spuds” for this upside down wreck, portending another clear water dive.  Again we jumped in, checked that everyone was ready and started our descent.  The Dredge is one of my favorite dives, with its inverted position, all the spools and rope hanging underneath, and the huge dredge shovel. On past dives on the Dredge, I had to piece together in my mind what the whole thing looked like from small 10ft.snapshots, but on Saturday, we could almost see it in its entirety. So cool!

We will definitely make some dates to do this again next year, but believe me when I say to get your money in ASAP once the dates are announced, or you will be missing out again!