Weight calculators for women divers / friend overweighted in pool?

[scuba_dude_los_angeles]

My friend is trying to get scuba certified and she rented gear. We're in Southern California, so these are cold dives which require a full wetsuit. My question is related to the pool, but also related to her weighting in the ocean. All of the online calculators suggest around 9-10 lbs of weight for ocean, and I even used the advanced buoyancy calculator after we calculated her personal buoyancy to also arrive at around 8 lbs of lead. I would expect the freshwater weight requirements to be less. But in her pool session, she was weighted with 18 lbs of lead (she originally dove with 14, then instructor added 2x2lbs of trim weight).

I wanted to know, was she seriously over-weighted? Or am I missing some variable here that would merit her requiring more weight than even I require (a 150 lb man) to dive? When I dive cold water with full hood, 7mm wetsuit, and my backplate (6.5 lb steel plate), I only add 10 lbs, bringing my total weight (backplate + lead) to 16.5 lbs.

Her weight: 118 lbs, athletic build
Rental gear: Scubapro Bella BCD + reg/octo + spg
Other gear: Fins and 7mm booties, mask and snorkel, and a swim cap (for the pool)
Lead: Originally 14 lbs of lead, then instructor added 4 additional lbs = 18 lbs of lead total

For the pool session she did not wear the full hood or gloves. She only wore a full 7mm wetsuit, fins, goggles + snorkel, BCD. She was diving with a Steel 72 tank..

I'm just wondering how common it is to overweight new scuba students during pool sessions? Even if I used the 10% rule, her weighting should be around 14 lbs. Or do our calculators under-calculate for women due to differences in body fat?

 

[Rilelen]

Yes, it’s common to overweight new divers, but it’s also true that new divers need more weight - and will drop a few pounds as they get more experience. The 10% rule is for a 3mm wetsuit - you will need substantially more for a 7mm wetsuit, and I find that rule of thumb works better for men than for women. Most women have substantially more body fat (hips, breasts) which makes us more buoyant than a man of the same weight.

In my experience, as a woman, a typical newly certified woman diver needs about 10-14 pounds of weight in saltwater in a 3mm wetsuit. Add approx 4 pounds to each increase in wetsuit thickness, so that would be 14-18 pounds in a 5mm suit, and 18-22 pounds in a 7mm wetsuit. Subtract 4 pounds for freshwater. That sounds awfully close to your friend’s weighting.

I’m a bit bigger than your friend, but I personally need about 16 pounds to sink in saltwater in a 7mm wetsuit (12 pounds in freshwater). That can be either lead weights, or distributed across a steel backplate/tanks. When I started diving those numbers were closer to 22 pounds in saltwater (18 pounds in fresh) - experience matters a lot.