It's also difficult for many large divers to find an appropriately sized weight belt. On several occasions I have watched overweight divers link two belts together. This is clearly a safety concern. Porcupines of the sea, urchin spines are like hypodermic needles that break off once deep inside you, injecting their venom. The venom from stonefish spines is delivered deep into the wound and produces excruciating pain that may last several days.
Stingrays use one or more large spines or stings on their tails as defensive weapons.
When you step on one, the ray thrusts its tail forward and upward, lacerating or puncturing your foot, ankle or leg. The increased buoyancy of adipose tissue means that obese divers must carry more weight in order to descend. I have seen divers in colder water load as much as 40 pounds on a weight belt when wearing a 6 mm two-piece wetsuit. If this weight is not well distributed, it can cause problems with buoyancy and balance at depth, as well as significant back and hip discomfort. Also, the problems caused by a too-tight BC can be compounded when it must be inflated to compensate for the increased amount of lead and loss of buoyancy at depth.