How do you treat hyperventilation while scuba diving?

Answer 1

If someone starts to hyperventilate when they are diving this is generally because they are inexperienced and are anxious. It can also be because of heavy exertion or in some cases incorrect breathing mixture. It can be set off by something as simple as water leaking into the mask or not being able to control buoyancy. It is normal for inexperienced divers to get excited and use up their air at a high rate. Experienced divers should always monitor the contents of less experienced divers cylinders as the dive duration is always set at the person who will use their air first. When fast breathing becomes hyperventilation is a bit of a moot point but is generally considered to be when partial pressures of CO2 drop and the blood becomes saturated in oxygen.

At depth it may cause greater problems than on the surface where you might just get light headed. There is no way of treating it (like you may have seen in the film The Abyss) for normal Scuba gear, although there may be ways to influence it with rebreather equipment. The best approach would be to carefully and slowly help the person to the surface, conducting required decompression stops as they will be using a lot of air and their dive time will be rapidly reduced. Keeping eye contact will probably help (unless you are really ugly!) and being on hand to control the ascent and ensure that person does not rocket to the surface is a plus.