Basic Weighting Guidelines for Scuba Divers
How much weight do I need for scuba diving ?
This is a tough question every diver faces from time to time. Although only a buoyancy check precisely determines the proper amount of Lead(weight) is needed, here are some basic weight guidelines that’ll get you started. These guidelines are based on individuals of average build, diving in saltwater. Lean individuals diving in freshwater may need less weight, heavy individuals may need more.
Basic Guidelines: Exposure Suit Type
1. Swimsuit or dive skin.
0.5 – 2 kg / 1 – 4 lb.
2. Thin (3 mm/I/16 inch), one-piece wet suits – shorties or jumpsuits.
5% of your body weight
3. Medium-thickness (Smm/3/I6 inch), Two-piece wet suit.
10% of your body weight
4. Cold-water (7mm/I/4 inch), two-piece wet suit with hood and boots.
10% of your body weight, plus 1.5 – 3 kg/3 – 5 lb.
5. Neoprene drysuits.
10% of your body weight, plus 3 – 5 kg/7 – 10 lb.
6. Shell-style dry suits* (using light-weight, nonfoam underwear).
10% of your body weight, plus 1.5 – 3 kg/3 – 5 lb
7. Shell-style dry suits * (using heavy-weight or foam underwear).
10% of your body weight, plus 3 – 7 kg/7 – 14 lb.
* Regarding shell-style dry suits – the lead needed beyond 10% of your body weight is primarily determined by the buoyancy of your underwear. The buoyancy of different underwear types varies greatly.
Conversion Estimates for Salt or Fresh Water.
Convert from saltwater to freshwater (or vice versa) using the following estimates.
Amount of Weight to add from (Fresh Water to Salt Water) or Subtract (Salt Water to Fresh Water)
45 – 56 kg/100 – 125 lb. 2 kg/4 Ib.
57 – 70 kg/126 – 155 lb. 2.3 kg/5 lb.
71 – 85 kg/156 – 186 lb. 3 kg/6 Ib.
86 – 99 kg/187 – 2I71b. 3.2 kg/7 Ib.
Estimating Weight Change Due to Air Consumption.
Depending on the type of tank you use, it can become 1-2 kg/3-5 lb. more buoyant by the end of your dive. The popular 80 cubic foot/12-litre tank will become approximately 2 kg/5 lb. more buoyant. To compensate for this increased buoyancy near the end of your dive, you may need to add some weight beyond the basic guidelines above.
Additional weight, beyond the guidelines, may not be needed for some types of steel scuba diving tanks.