Don’t Make Overweighting Your Invisibile Assistant 5


No overweightingThere is an instructor practice that we’ve all seen but I don’t think any of us has actually commented on it. The practice is using the bottom (pool, sea, training platform in quarry or lake) as a training assistant. This is actually the basis for exercises such as fin pivots and other exercises that do not teach proper buoyancy control. This practice is widespread and entrenched in teaching exercises starting at Introduction to Scuba on up.

By overweighting students, the instructor can “nail” them to the bottom and they don’t float away. In open water, Instructors are allowed to supervise up to eight students in training (more with certified assistants such as Divemasters) so they “nail” them to the bottom so they don’t float away.

overweightedI recently overheard a seemingly very competent instructor briefing his four students prior to an open water training dive. One of the exercises was to be an Emergency Swimming Ascent.

As he advised his students about the procedures to be used during the diving exercise, he counseled them to kneel in a line on the sandy bottom. He would summon each student over to his location at the base of an anchored buoy where they were to stand on the bottom next to him. He further advised that he would give them a signal to ascend and they should bend their knees and push off the bottom to initiate their ascent toward the surface.

Overweighting student divers and “nailing” them to the bottom like so many beanbags is a lazy and counterproductive form of control. As we’ve said way too many times, student divers should be taught to practice proper buoyancy control techniques from the beginning of their training.

If instructors require the use of the pool or sea bottom to control their students, perhaps they should reduce the instructor student ratio to something that they can handle properly and safely.

Your thoughts? — John Wall

John Wall has been a friend and mentor for a number of years. It was John who first turned me on to the fact buoyancy control should be taught as a habit and not as a “skill.” John and his wife Suzy ran an extremely successful dive store in the DC suburbs for a number of years before retiring to Bonaire. Today, their “retirement” consists of running Buddy Dive Digital Photo at Buddy Dive Resort in Bonaire.


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5 thoughts on “Don’t Make Overweighting Your Invisibile Assistant

  • Tom Nelson

    we use the roof of a bus as the base for open water skills, CESA included. The students are however weighted properly so with the slick slight curvature of the bus they require good breath control to keep from sliding around. During CESA we move to them and have them ascend, the 4 dive teams each have a position on the bus and they don’t move from that position until an ascent is initiated, each of the OOA ascents, and the CESA. That is dive 1, and after that they don’t kneel. Rather difficult to complete the skills checklist while hovering for most of them, so while they are kneeling on the bus, it is only to execute a specific set of skills that we have to evaluate per NAUI and cranking them out in one go like this is easiest, even if it was only 1 dive team. The skills required include achieving neutral buoyancy using both oral and power inflator so they have to kneel on something at some point, irritating and would be nice if NAUI would do away with half the damn checklist, but alas, no dice.

    The rest of the dives have more relevant skills practiced while hovering, arrive at a destination and record depth/air/time, arrive at destination and change heading on compass, etc.

    • Admin Post author

      If it’s what I think it is, I know that bus all too well. It’s about all I ever get to see of Fantasy Lake. You bring up an interesting point, though. NAUI likes to pride itself on the fact they require roughly 50 percent more entry-level skills than most other agencies. Unfortunately, they don’t also mandate that NAUI courses be 50 percent longer to accommodate this. What often ends up happening is that repetition of critical skills is sacrificed in order to make time for inconsequential ones. The result can be less-capable divers, rather than more capable ones. Juat another case of people mistaking quantity for quality.

  • Reza Gorji

    Hello Harry:
    Thank you for your informative website.
    Can you write a section on tank selection? If and when you do, could you please make a note of how the diver is supposed to compensate for the varying buoyancy between a full and a tank near the end of the dive.
    Thanks.

    • Admin Post author

      I just recently did a video and an article on tank selection for recreational divers for SDI. It will be posted on their blog shortly. Luxfer and Faber both post cylinder specs on their websites, including weight and buoyancy, both full and empty. The only buoyancy figure that counts is how positive or negative a tank is when near empty. That is when you should be doing your weight check. The fact a tank will be heavier at the start of the dive is of less consequence, as you would compensate for that with the BC air cell. Although, if diving large doubles, your tanks may be substantially heavier at the start of the dive than if using a lightweight single. Your BC air cell must be large enoungh to accommodate this.

  • Lance Velez

    Great article ,I really enjoy reading your stuff it is no nonsense and practical. There is so much crap in the “educational” systems of the big agencies that churn out poor Divers who think they were taught correctly .