Using an alternate air source

In the PADI Open Water Diver course, you learned several ways to handle running low on or out of air, including using an alternate air source. This usually means using your buddy's extra second stage, but consider using an independent alternate air source (pony bottle or self contained ascent bottle) for more self reli­ance, especially when diving in more challenging environments such as currents, limited visibility or depths below 18 metres/60 feet. Since pony bottles and self contained ascent bottles hold addi­tional air and function indepen­dently from your primary scuba, you can make a safe independent ascent in the event of unexpected air supply loss. Of course, you and your buddy should always plan your dives with an ample air reserve so you don't run out in the first place.

You probably recall that vertigo is the unpleasant experience of losing your orientation when ascend­ing or descending so that you can't tell whether you're going up or down. Dizziness often accompa­nies vertigo, with potential hazards if you become significantly disoriented. To reestablish orientation quickly, make contact with a stationary reference, such as an ascent/descent line or the bottom. If you're in midwater and lack a stationary reference, checking your depth gauge and watching your bubbles may reorient you. It often helps to make contact with your buddy.

Touch fasteners

Known commonly as "Velcro TM" after the most popular brand, touch fasteners join fabric to fabric. You'll find touch fasten­ers used on BCD cummerbunds, and to take up slack when you adjust nylon webbing. Nylon tank bands, for example, usually have touch fasteners to hold the web end after you cinch the buckle dom.

Touch fasteners wear out, and they can get clogged with sand and lint, making them less reliable. Therefore, they're not commonly used for weight belts or to hold significant loads. Inspect the material for wear and replace it as necessary.

Tows

When giving in water rescue breaths, you tow the victim in the position you use for giving breaths, whether mouth to pocket mask, mouth to mouth or mouth to snorkel. A second rescuer can make things easier for you, though, by pushing the victim with the modified tired swimmers carry.

If the victim is unresponsive but breathing, gener­ally you'll want to use the underarm tow because it keeps you where you can easily monitor breathing and responsiveness. Note that victims can become responsive and then unresponsive again, or can stop breathing and then resume breathing inter­mittently so it's important to watch breathing and responsiveness. The main priority is to tow the victim to a stable, secure environment as quickly as possible.

Quick disconnect fasteners

You'll usually find quick discon­nect fasteners used for BCD chest and shoulder straps, for attaching accessories to weight belts or BCDs, and sometimes to attach fin straps. Occasionally a diver may use a large one as a weight belt buckle.

Quick disconnect fasteners release easily by squeezing them, even under strain. They may become less reliable with heavy wear, however, so that they pull free unexpectedly under strain. Also, putting too much strain on one may cause it to pop free. To prevent these problems, inspect quick disconnect fasteners for wear, and use one large enough for the load