Can Kids Dive?

By Dr. Sawatzky

Recently, some agencies have started to teach diving to even younger children. In this column, we are going to look at some of the medical concerns with young divers. There are several anatomical and physiological differences between kids and adults that might be relevant to diving.

The first is that the bones are still growing in children. At each end of the bone, near the joint, there is an area where the bone is actively growing called the 'growth plate'. If the growth plate is damaged, for example by trauma, it may stop making new bone and the bone will stop getting larger. This can result in significant problems such as one leg that is much shorter than the other. The concern with diving is that the growth plate might have an increased susceptibility to decompression sickness because it has an increased blood supply compared to the rest of the bone. If that were the case, and if the person developed DCS in the growth plate, the growth plate might be damaged and stop producing new bone.

An easy way to reduce the likelihood of this problem is for younger divers to be more conservative and not push the decompression tables/computers to the limits. But, at what age do the growth plates stop growing? We all remember growing rapidly taller when we were in our mid-teens, but if we think carefully, we continued to grow, how be it at a much slower pace, for several years afterwards. The long bones in the arms and legs stop growing by about age 16 in girls and 18 in boys but the growth plates in the vertebrae in the back do not fuse until the mid twenties! So, is this theoretical problem a real practical concern?

The bottom line is that we do not really know. The only safe option is to advise
younger people to dive more conservatively to reduce the probability of growth plate damage due to DCS.

The second physiological concern with kids diving is that the younger the population, the more individuals will have an open or patent foramen ovale. A patent foramen ovale allows bubbles to pass from the right to the left side of the heart, changing them from virtually harmless pulmonary gas emboli to potentially fatal arterial gas emboli. It is vital that younger divers do not conduct dives where bubbles are formed. This means they must stay well-inside the no-decompression limits.

The third physiological concern with kids diving is their smaller size and reduced muscle mass. It is dangerous to go diving when the diving equipment does not fit properly (tanks too big and heavy, buoyancy compensator to large, fins over-powering the leg muscles, etc.). This problem has largely been corrected by the development of special equipment for women divers. They tend to be smaller and therefore teenagers of both sexes can now usually obtain diving equipment that fits properly. More recently, even smaller gear, designed for young teenagers and children, has appeared on the market. Kids have smaller muscles and therefore cannot deal with full sized adult gear. This is not a problem if they have their own equipment, but can they be an effective buddy if their dive partner has a problem?

This is a major concern of mine, for divers of all ages. Each diver must be able to assist their partner in an emergency. How is a 50 kg woman going to help her 125 kg dive buddy if they have a problem? This is obviously a major concern if kids dive. One solution is to always dive as a threesome (two larger persons and one smaller, or one larger person and two smaller persons). In this case, the team can always deal with a problem experienced by one of their divers. The problem with this approach is that three-member dive teams turn up far too often in dive accidents and are inherently more dangerous. The minimum size for a diver, for purely practical reasons, seems to be approximately a weight of 45 kg and a height of 150 cm.

The next concern with kids diving is the problem of hypothermia. Heat loss is proportional to body surface area and inversely proportional to body mass. What this means is that
small people have relatively more skin area in relation to their total body weight than larger people. Therefore, small people cool down much faster than larger people in cold water. Kids obviously have this problem. In addition, kids are changing their size and shape rapidly as they grow. Therefore, it is an almost impossible task to keep the rapidly growing person diving in a wetsuit that fits properly. If the wetsuit does not fit well, the diver will get cold very easily. Drysuits are only a partial solution to this problem as the child will still rapidly outgrow the drysuit and it will have to be replaced. In warm water, this is a smaller concern, but last time I checked, Canada does not have an abundance of warm water diving!

The remaining concerns with children and young teenagers diving are primarily psychological. Can they truly appreciate the dangers of diving and learn how to react appropriately in an emergency? Kids can be extremely 'cool' divers, because they have absolutely no idea that what they are doing can be dangerous! To understand the dangers of diving, you have to be able to understand the gas laws, do some simple mathematics, and understand some basic anatomy and physiology as it relates to diving. It has been my personal experience that most children have trouble with these concepts until they are at least 12 or 13 years old. Children grow up and mature at vastly different rates. Therefore, it is impossible to determine an exact age when they can be safely taught to dive. The bottom line is that they have to have the physicalsize as well as the mental and emotional maturity to not only understand the dangers of diving and take care of themselves in an emergency, they must be able to assist their dive buddy. There should be only one standard to be certified as a diver and therefore, younger divers should meet the same standards as adults.

All divers must have good judgment, responsibility, attention to detail and respect for rules. Many teenagers have problems in these areas. These limitations really determine the minimum age to take up diving.

My last comment is that no one, including young people, should be taught to dive and be certified unless they really want to dive. Diving for the wrong reasons is very dangerous. So what do you do with children who are not yet ready to take up diving? They can to taught to snorkel, swim in waves and currents, swim underwater, etc. These are all very useful skills to have when they take up diving when they are older.