Diving hoods do several things. First, they keep your entire body (including your head) warm. Your mother likely told you to wear a hat when you stepped outside on a cold day, and research has proven that she was absolutely right. About 60% of body heat escapes through the head, so when we go outside on a cold day without a hat or when we dive without a proper hood, our bodies need to work much harder to stay warm. On a dive, this extra energy expenditure can affect the quality and length of our dive. A hood helps us maintain a good body temperature, even on cold-water dives.
In addition, a hood keeps our hair from getting in front of our eyes or getting entangled in seaweed or other obstacles underwater. Therefore, even divers in warm water will likely need a hood some of the time.
Hoods work in some ways like hats – they trap heat before it leaves your body. Diving hoods are also more sophisticated than your favorite winter hat. Many of today’s diving hoods are made from a material known as neoprene. Neoprene is made from many tiny air bubbles, making it spongy. The air bubbles trap the body heat of the diver more effectively than a winter hat. The hood also traps a small amount of water near the diver’s head. The body heat warms the water that is trapped in the diver’s hood, which keeps the diver warm and comfortable.
When choosing a diving hood, you will need to consider:
1) Warmth. If you dive in cold water, of course, you will need a warmer hood, or rather a diving hood that keeps you warmer. If you are diving in cold water, look for neoprene diving hoods with more thickness. A 7mm hood, for example, will keep you much warmer than a 3mm diving hood. A 3mm hood made from nylon or neoprene is generally suitable only for a warm-water dive.
2) Coverage. The more your hood covers your face, the warmer you will be. Dive hoods for cold water diving have bibs which tuck into the wetsuit. Cold-water diving hoods also cover quite a bit of the diver’s cheeks, jaw, chin, and forehead, so that very little of the face is exposed to the cold. If you are diving in cold waters, look for a large bib as well as maximum coverage to stay warm. If you are diving in warm waters, you will not need or want the extra coverage. Keeping less of your face covered, in fact, will improve your mobility and potentially your peripheral vision.
3) Movement. If you are diving in cold water, your main priority will be to stay warm. However, if you are diving in warm water, you will be able to consider movement. Look for hoods that allow you to move less cumbersomely. Nylon hoods are ideal for maximum movement in warm water.
4) Fit. Your hood must fit correctly in order to function correctly. If your diving hood is too small, it will tug at your neck, throat, and face. Not only is this uncomfortable, but it can be distraction and can inhibit natural movement on a dive. If your dive hood is too large, water will easily flow in and out of the dive hood. This will not allow your hood to trap heat effectively. On a cold-water dive, a too-large hood is dangerous as it will simply not keep you warm enough.
5) Zippers. Not all dive hoods have zippers, but some have zippers along the back of the dive hood. If you have long hair, you might want to look for this style of dive hood. Zippers make it easier to put on and take off your dive hood. Zippers can also help prevent the hood from tugging on your hair when you’re putting your dive hood on or taking it off.