• How much weight will I need?
• What's in your spare kit?

HOW MUCH WEIGHT WILL I NEED?

My first recommendation here is to keep a log book and record how much weight you used on every dive, the thickness and type of exposure protection you used, the type of tank you used, and whether you had too much, too little or the right amount of weight. This will allow you to refresh yourself when you are exposed to same conditions and provide a starting point as you make changes to what you are diving with.

When determining how much weight a diver should use it is important to consider the type of tank being used during the dive. Many divers find themselves weighted just right at the beginning of the dive only to become positive half way through. This happens because of what the compressed air in the tank actually weighs. As the diver’s air pressure (PSI) drops, the tank becomes lighter.

Air weighs .08 pounds per cubic foot. When compressed into a scuba tank this becomes a significant factor to take into consideration. For example, if your cylinder holds 100 cubic feet of air, the air in that tank weighs 8 pounds. Thus, half way through the dive, when the cylinder is half full, you have “lost” 4 pounds of weight. Plus the cylinder itself has buoyancy characteristics that can alter how much weight is needed.

An Aluminum 80, one of the most popular size tanks in use today holds approximately 80 cubic feet of air. This compressed air weighs 6.4 pounds. The cylinder itself weighs about +4 pounds in the water when empty and thus floats. Conversely, when full the tank weighs -2 pounds and thus sinks. At 1500 PSI the tank is positively buoyant by about 1 pound. At 500 PSI the tank is positively buoyant by 3 pounds. Consider the importance of performing a controlled ascent with a safety stop at the end of a dive. Envision how an improperly weighted diver could be affected. The diver must carry weight to compensate for the requirements and changes of the total diving system. This is why a properly weighted diver will float at eye level, holding a normal breath WITH A NEARLY (500 PSI or less) EMPTY TANK.

WHAT’S IN YOUR SPARE KIT?

"Do I really need a spare kit?" is one of the more common questions I get from students. My answer is always the same: "No, unless you don’t want to miss a dive for which you just paid $100". I have yet to find the dive operator who will refund your money if you are unable to make a dive because of equipment malfunction. Not to mention that you have probably spent a fare sum to get to your dive destination, have limited dive days available, and do not want to spend your shore time searching for that obscure mask strap.

It’s simple: EVERY DIVER SHOULD HAVE SPARE PARTS KIT! So whats in your Spare Parts Kit?

A proper kit should include the equipment specific items for scuba system considering the types of diving you will be doing. If you will be diving at night, you might wish to have extra batteries and a spare bulb. All diving requires the use of a tank, so spare orings should be in everyone’s kit. Your kit might also include:

Fin strap – Break a fin strap and your $100 fins are nothing more than pretty accessories. Make sure you have a fin strap that will work with your buckle system

Mask strap – This is an inexpensive part that can save your dive. If your strap breaks and you don’t have a backup, YOU CANNOT DIVE! Make sure that the backup is the same length and thickness.

Spare mask – As an instructor I have acquired a nice mask collection. My collection comes not from purchase but simply picking up masks that have previous divers have somehow dropped or lost at the dive destinations. A backup mask solves the problem. If you lose your mask or if your buddy’s accidentally sets his tank down on your mask, you a have a backup.

Snorkel Keeper -- Keep this one simple: just an old fashion figure 8 keeper will do.

Tie-Wraps – A whole lot of things can be fixed with a tie wrap. Keep a handful in your kit.

O-rings – Keep a variety of sizes (including tank o-rings) along with compatible lubricant (Regulators certified for use with Nitrox require CristoLube. Never use silicone on a Nitrox regulator).

Spare clips – Clips have a way of breaking a disappearing. Keep an assortment of extras.

Spare mouthpiece – Have you ever dove with a mouth piece that had the tab bitten off? If so, you know why this should be in your spare parts kit.

Mask Defog – Spit just does not work very well. Keep an extra bottle of defog in case you run out or someone “borrows” yours.

Tools – A pair of adjustable wrenches, pliers and a small screwdriver or two can save a dive. Buy quality here as salt water can be hard on tools. The universal tool is a great accessory that provides a number of different tools in a compact package. Plus this took has Allen Keys, which are required to fix many regulator issues.

Last you need a way to carry your spare parts. I prefer a small, pelican type dry box. Trident makes a tube already stocked with many of the above items.