2012-11-01

Hoods

Drill in the Sauerkraut. (Diver's Aufkirchen, BY/D)

There are always these things that ‒ for whatever reason? ‒ you will never find in the training or instruction books. Things, that you only get to by asking old hands or finding out for yourself. When it comes to diving with full face masks, hood are such a topic. «Hoods?» you may ask in surprise. Yup, that's correct.
My Suggestion: Make sure to put on your hood and check diving with it and your full face mask while still training in the pool or confined water. This way you gain important practise and get acquainted to your full face masks peculiarities when dived with a hood. Please make sure that you also drill emergency situations. When you are confident with the procedures, add thick gloves to your drill. After that you should be well prepared for your first full face mask dive in open water.

Hoodology


The most basic decisions revolve around these two topics:
  • neoprene hood or latex hood?
  • is the mask to seal with your hood or directly with your face?

    Hoods: Neoprene or Latex?


    Hood with smooth skin neoprene
    on both the inner and outer side
    around your face.
    That more or less depends on your personal preferences. *snicker*

    Any joking aside, you probably need to check out this for yourself. Some like to combine full face masks with the traditional neoprene hoods, while other strictly prefer latex hoods (typically of the heavy duty and thus durable kind). Depending on personal preferences you may wear an additional fleece hood for added warmth under the latex hood.

    For neoprene hoods, a common material thickness is 5mm. There are also 7mm thick hoods, but these tend to be catalogue fantasies in some regions of the Earth and almost non-deliverable.

    In any case, your hood should have a small hole or valve at the crown or back of the head to drain off excess air. But later more about this topic.

    Sometimes neoprene hoods also get reflective patches in order to better spot divers even in bad weather conditions.

    Since the neoprene hoods are easier to get over here (as this hood type tends to be ordered by special operations divers from Police, Fire Service, SAR in Germany), I've sticked with them. With time, I got accustomed to them, as they are warm. I also have to admit that I've come to like the reflective patch pattern of the Northern Diver neoprene hood.
    From My Experience: I'm getting the impression that online shop or catalogue images are rather symbol photos. Whatever hood you order, you'll be delivered a different one. And to put insult to the injury, order the same hood twice and you'll end up with two different types of hoods. Northern Diver takes the cake for sending us one XL-sized full face mask hood that was completely different from the L-sized hood, albeit all sizes used the same ordering product ident. Another manufacturer, Bare, claimed that the hood that you can also see below were never manufactured by them. Oh those dirty Asian Sea product pirates ... they are in the business of cloning non-existent full face mask neoprene hoods? Really?!

    Full Face Mask: On Your Hood Or On Your Face?


    Full face mask
    sealing to your neoprene hood.
    Albeit you don your full face mask always after donning your hood, there are basically two different parties when it comes to «hood bearers»...

    in one variant, the full face mask seals to the hood and therefore overlaps it. Most neoprene hoods sold for use with full face masks are designed for this variant. In consequence, the face opening is often rather narrow; very similar to how hoods for ice diving are designed.

    With this variant, it is important that the zone where the full face mask seals to the hood is made of double-sided so-called smooth skin neoprene. This ensures that not only the mask seals to the hood as good as possible, but also the hood to your face.

    in the other variant, the full face mask seals to your face instead. In most cases you need to cut out a suitable area of your hood. One way to do this is to first don your mask with your (unmodified) hood already on. Then let somebody help you to mark the outline of your mask sealing to your hood. Afterwards, cut out a suitable area; either completely or let the mask seal partly overlap and thus seal to both your face as well as to the hood.

    ATTENTION! In any case you must be able to quickly remove your full face mask under any circumstances, such as in emergency situations. Thus, never put the hood above your mask, always put the mask above the hood.

    Letting Off Steam


    A hole or valve in your hood
    ensures that excess air
    leaves your hood before
    causing trouble.
    In any case when diving with a full face mask your hood need to have a hole or valve to ensure that excess air leaves your hood. Otherwise air entering your hood from your mask can trouble your buoyancy. Even if you wear the full face mask so that it seals to your face, leakage air leaving your mask may get trapped in your hood. The hole or valve should be either at the hood's crown or the back of your head.
    ATTENTION! Too much (excess) air in your hood can be a dangerous situation, messing up your buoyancy. You need to react quickly to this situation and thus need to train proper handling. This is similar to training how to handle excess air in a dry suit, albeit the particular handling is different.
    Hood holes or valves tend to be properly centred to keep symmetry ... just where the head strap of your full face mask usually will be. If you're unlucky, then this head strap will cover the hole, defeating its purpose.

    For this reason, some hoods have their holes at the back of the head. Beside getting out of the way of the middle strap this point usually becomes the crown point while diving in a horizontal position. Some full face masks feature a mask spider construction that (rather by accident) avoids covering hood holes.

    Despite all these constructive means, holes and valves are not covering all eventualities. Depending on how well your hood fits your head and depending on the diving position and conditions you will nevertheless notice more air entering your hood than leaving it.
    No excess air, please.
    My Suggestion: Make sure you train such excess air situations in your hood in a pool or confined water. At first, you may find it difficult to get excess air into your hood. But over time you'll surely learn how to pump up your hood. I found my head position of importance in order to fill my hood with mask air.
    My Suggestion: One trick to provoke excess air is to pull up your hood slightly in its chin area and to grimace so that the hood covers your mouth. Then breathe in through the nose and breathe out through the mouth. This should bring at least some air into your hood.
    Unfortunately, while this whole topic is usually mentioned in training books, it is often neither covered in detail nor in a suitable form. In consequence, you won't find any drill exercise. This is also partly due to the problem that the student first needs to learn how to bring excess air into the hood. And often, time is money. And both instructor and teacher are eager to finish the drill as quickly as possible. After all, they want to dive, not to learn. A dangerous attitude.

    To be honest: ever met an instructor drilling his/her students with a hood in a warm pool?

    Somehow this reminds me of that sweet secluded driving school areas you can find in some countries. What you learn there is in no way related to the traffic jungle outside. (On a sidenote, over here in Germany, we are training in full traffic. I even managed to finally drive my examiner crazy after he made me to visit all traffic calmed areas in town.)

    When you get too much excess air into your hood for whatever reason you need to react: make sure that you stop its cause (such as a free flowing reg). For instance, change your position in water so that the air takes a different route instead of getting into your hood. In addition, get the excess air out of your hood. For instance, you can use your hands and swipe air out of your hood. See above for how this looks like.

    Head Banging Bubbling


    Another thing you normally don't get told in advance is that diving with a full face mask may sometimes be loud. Not so much for your buddies but instead for you. So why?

    Small leakages that also change with your diving position may happen all the time; usually they are of no concern. And they happen even if you carefully and accurately donned your full face mask and checked its sealing three times. Unfortunately, sound travels really good in water, so you can perfectly hear all the sounds these small leaks produce. Depending on the overall situation and your stress level this may sound terrible and cause you unpleasant distraction.

    In particular, inexperienced beginners may get afflicted in particular. In the worst, they get too stressed and react wrong in a difficult situation, making the situation much worse than it is.
    My Opinion: On this backdrop I personally am the opinion that dive beginners should not at the same time start diving with a full face mask for safety reasons. Even in a warm, seemingly safe environment the overall inexperience of beginners may put them into real danger when in case of a full face mask problem both sight and gas supply gets lost simultaneously. Leaning to dive thus should be clearly separated from learning to dive with a full face mask. Full face masks are not for dive beginners, not for trial, and also not for fun diving by inexperienced OWDs and fresh AOWDs.
    Personally, I would like to see the dive training organizations to take on a clear position. At this time, these rather seem to be primarily interested in making money fast and easy. Restricting students to enter some specialties on the basis of safety reasoning cannot be seen at least for now.
    If you look closely, you may notice small streams of bubbles appearing in some photos in this blog. It's true: I'm leaking, too...

    Pressure Equalization


    Another topic usually missing from the books. But how is pressure equalization related to hoods? No big deal at all, but worth mentioned nevertheless.

    As I already mentioned above, there may be some air leaking out from your mask into your hood. If you flooded your hood at the beginning of your dive, this air may push out some of this waters with your ears and ear canals falling dry. During your dive under different conditions you hood then may unexpectedly start to seal your ears due to changes in pressure. In the end, you may then find it difficult to do normal pressure equalization.

    In a similar way, the outer pressure situation may cause the hood to seal your ears against water so that this also causes a lower pressure in your ear canals and the hood, compared to your mask and water pressure.

    You can correct the situation by either bringing air into your hood. You already learned how to do this when you learned to deal with excess air in your hood. So this skill now comes in handy. Another way is to lift your hood slightly so that fresh (and bloody cold) water enters it.
    From My Experience: Don't be surprised to constantly feel water leaving and filling your ear canals. Bad luck, the pressure situation then just is this way and you have air in your hood (which you will have most of the time in small quantities anyway). This may be annoying but you need to get over it.

    More...


    You will find even more blog posts on this topic following this tag: full face mask. Likewise, I've put some impressions from diving with full face masks online.

     


    PS: The imagery in this blog post comes from my own stock of selfies, shot in the Diver's Inn in Aufkirchen.
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