“Properly Weighted Divers
Float at Eye Level”

Much of what has become recreational diving dogma reflects the sport’s Southern California roots. At one time, what were then the four largest training agencies (NAUI, PADI, SSI and NASDS) were all based in Southern California. If you look at older textbooks, you get the impression the only diving to be done anywhere in the world involves surf entries off Southern California beaches.

Today, recreational diving has become much more Caribbean-centric. Of the major training organizations, only PADI remains in Southern California. Nevertheless, one vestige of diving’s SoCal heritage is the notion that — regardless of the type of exposure protection worn — a “properly weighted diver” will float at eye level at the beginning of the dive. You’ll find a statement to this effect in nearly every major diving textbook.

Guess what? If you happen to be diving off a Southern California beach — or anywhere else where diving involves a full-length 7mm wetsuit and a lightweight single cylinder — this statement is generally true. It is generally not true if you are diving a lightweight wetsuit or dive skin in the Caribbean, or a shell dry suit in Lake Superior. It is also generally not true if you are diving a higher capacity cylinder and will be consuming more than three to five pounds of air during a dive. Why is that?

• The “float at eye level” principle assumes all divers will experience the same amount of buoyancy loss through suit compression that divers wearing 7mm wetsuits do. This is not true of divers in 3mm wetsuits and dive skins who, if they float at eye level at the beginning of the dive, may have difficulty getting and staying under water.
• Divers in shell dry suits will be maintaining a constant volume of air in their suits, regardless of depth. Therefore, it is as though they experience no suit compression at all. A properly weighted dry suit diver, with his lungs half full, will just touch the surface of the water with the top of his head…at the end of the dive. At the beginning of the dive, when his tank is heavier, he should sink under the same conditions.
• The “float at eye level” advice given in so many textbooks generally fails to address the issue of the weight of the gas divers consume during their dives. This can vary widely from diver to diver, depending on gas consumption rate and the size of the cylinder used.

Bear in mind, the traditional, pre-dive weight check does have some value. It can help identify whether a diver is grossly overweighted or underweighted. For fine tuning a diver’s weight requirements, however, the best time to do a weight check is not at the beginning of the dive, but near the end. Why is that?

• Every diver’s goal should be to use the least weight possible. Doing so makes divers less dependent on BCs for buoyancy adjustments, improves body position and makes divers more likely to survive in the event of BC failure. Less weight is also a lot easier to carry around.
• Divers will need the most weight at the end of their dives, when making safety stops. This is when their tanks will be the lightest, and — in so far as this is the shallowest they are likely to be for any period of time — it is when their suits are the most buoyant.

Thus, the best time and place to conduct a weight check is while making your safety stop at the end of the dive. The procedure is simple enough: Just make certain your BC is completely empty. If properly weighted, you will be able to hover, effortlessly, at safety-stop depth with no air in your BC.

The beauty of this approach is that it works regardless of the type of exposure suit worn or the size of the cylinder being used.

After you have done this often enough to get your weight dialed in for a variety of exposure suits, go back and see where you float at the beginning of the dive.

• In a 7mm wetsuit, you most likely will float at eye level with your lungs completely full, or at forehead level with your lungs half full — just as the textbooks suggest.
• With a lightweight exposure suit or dry suit, however, you will most likely float much lower than this.

That’s why blanket statements such as “properly weighted divers always float at eye level” are just so much unvarnished bullshit. Instructors — and their training organizations — should really know better.

“Buddy diving is safe. Solo diving isn’t.” »

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