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Thermal Protection |
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The waters off northern California are cold enough to cause most of us physical pain when unprotected hands or feet are immersed for more than a few minutes. There does exist an occasional freak of nature (and most marine biologists) who can work for extended periods without gloves. And I know of at least one guy who's willing to get a limit of abs buck naked in support of the right charitable cause. The rest of us, however, need plenty more thermal protection. A full body wetsuit, booties, gloves and a hood make up the typical wardrobe of a working abalone diver. Shorepickers can get away with quite a bit less: usually the hood is not needed and booties are often replaced by sneakers or other street type footwear. So the following discussion focuses on a diver's needs; others can take stock accordingly. Starting with the simplest and cheapest setup, the standard wetsuit for an abalone diver is a two piece combination of farmer john pants and dive jacket. Both articles are constructed out of 7 mm (1/4") thick neoprene. The result is a suit that wraps the diver's torso in 14 mm of neoprene while the legs and arms are covered by a less constricting 7 mm layer of rubber. If properly fitting and if the neoprene is in good shape, this combination is quite warm and cozy for freediving sessions lasting an hour or two. Nice and simple in theory. In practice, things are always a bit trickier. The enemy of heat retention is water movement through the suit. The less water moving through the suit, the warmer the diver. In order to minimize water movement, a properly fitted suit is snugger than any non-diver can imagine. I'm talking really really tight. A perfectly fitting, brand new wetsuit can be hard enough for a new diver to get into that just having enough hand strength to pull up the pants can quickly become a personal crisis of confidence. Putting on your dive pants is less an exercise involving one leg at a time than something along the lines of a comedy skit involving panty hose, tugging and some grunting. |
And then there's the two ordeals of putting on a dive jacket. First, you have to get your forearms all the way into the jacket sleeves. What sounds obvious here doesn't extend to being easy. Even the 97 pound weaklings among us seem to have Popeye forearms when it comes time to slipping into those sleeves. It always happens that you get your arms 3/4s of the way into the sleeve where nothing more is willing to budge. Working the rest of the arm into the sleeves can take a lot of time and energy. One trick that's commonly used (and curious for the uninitiated to witness) is to have a dive buddy blow into a sleeve at the wrist when you're convinced your arm can't go in any further. The idea is to kind of blow up the sleeve just a little bit letting the forearm slip the rest of the way into the sleeve. It's also a great ritual for getting closer to your dive buddy.
As an aside, both the snug pant legs and jacket sleeves tend to break in with use and getting into your own wetsuit gets progressively easier; they seem to learn your proper shape. That's the good news. The bad news is that the easier a wet suit is to get into, the colder that suit is in the water. About the time getting into the suit is no sweat, it's time to replace it.
The second ordeal to getting into the jacket is zipping it up. Consider that, once completely zipped up, a properly fitting jacket is going to be very very snug through the chest and stomach. It only follows that getting that zipper moving involves a lot of tugging and gut sucking (women don't usually have the gut problem but their hips present challenges I've never had to contemplate). There's nothing that's quite so much a relief in ab diving as getting the zipper snugged home.
That relief is short lived if, as happens more often than anyone would expect, you realize that you forgot to put on the farmer johns before the jacket. Not that that has ever happened to me; I never did develop the habit of putting on my shirt before my pants. But I can tell you from personal experience that the process of getting into a wetsuit can be tiring and, on a nice day, can work up quite a sweat. It's worth mentioning here that standing around fully suited up on anything but a chilly day is not a good idea. Overheating is a real possibility that is aggravated if the delay getting into the water is protracted or if there's a hike from where you suited up to where you're getting in. Most experienced divers partially suit up at the vehicle, make their way to the entry point and then put on their jacket, hood and gloves. This is definitely something where you don't want to get ahead of yourself.
If it seems like I'm making the process of suiting up sound more difficult than it possiblity could be, you underestimate my charity. Getting into a wetsuit has been so difficult for so long that the neoprene used to make wet suits has evolved to address those difficulties. Almost universally, wet suits today are made with neoprene sandwiched between an inner and outer layer of some nylon fabric. On the inside, that liner material can be like a thin layer of terry cloth. It's much easier to get into one of these "lined suits". But the same liner keeps the neoprene layer off the skin and, by extension, allows more water to flush around inside the suit. Sadly it's true that the easier-to-get-on lined suits are inherently less warm than unlined suits.
Just as the lining material is meant to make it easier to get into a suit, so is each and every zipper added to the suit. You'll find suits with zippers at the bottom of the legs, the last 6" of the sleeve and a long zipper to close the jacket. Each of these zippers is quite effective at making it easier to get into the suit. Unfortunately, those zippers are not very effective at keeping water out of the suit. Net result: the more zippers, the colder the suit.
The direction all of this is taking us is obvious: if you want the warmest suit possible, you're looking for one that's "skin-in" unlined (meaning the smooth side of the neoprene to the inside of the suit) and has a grand total of zero (0) zippers. These suits do exist and, for serious freedivers spending long hours in the water, they're hard to beat. But talk about a challenging suit to get into. Unlined, dry neoprene absolutely will not slide across skin. Period. Think about a smooth rubber surface here. It sticks to skin like Saran wrap sticks to itself. The only way to get into an unlined suit involves the liberal application of some lubricant. Talcum powder, corn starch or water mixed with hair conditioner are all popular lubricants used by aficionados of unlined, skin-in suits. In return for these hassles, the unlined suit provides incomparable warmth thanks to almost no water flushing through the suit. It is not at all uncommon to watch a diver doff a skin-in wetsuit and notice that the talc on his chest and back is bone dry. That's a measure of how little water gets into this type of suit.
So advantageous is a skin-in suit that even the mass-market wetsuit manufacturers have been pursuing a solution better than powders or hair conditions. In the past few years, coatings have been added to the skin surface of unlined neoprene. These coatings make the rubber skin slippery without lubricants and are, indeed, a nice development. The coatings aren't as good as the traditional lubricants but they do make skin-in suits tolerable to a larger segment of the market. Those coatings also tend to be found only on the higher end suits.
The really challenging part of an unlined, zipper-less wetsuit is the zipper-less part. The pants aren't too bad but a zipper-less jacket is more like a very tightly fitting jersey. Getting into one of these jackets relies on the neoprene material being stretchy enough to offer some give. The mass-market manufacturers balance stretch with neoprene density. Neoprene is basically foam rubber. More and bigger bubbles means stretchier neoprene. It also means neoprene that is less durable than denser materials. And it means greater compressibility at depth, a concern for SCUBA divers. The best suits are made with neoprene available from one of two sources. As far as I know, no commonly encountered brand name wet suits fall into this category.
But I'm getting ridiculously far afield for 99+% of north coast ab divers. Basically, even the cheapest 7 mm wet suit is more than adequate for the vast majority of abalone divers so long as it is reasonably decent shape and fits the diver well. It must be noted that while a suit must be very snug to be warm, some caution is needed when it comes to suits or hoods that constrict the neck. Too tight of suit/hood around the neck can have some very dangerous physiological side affects for someone about to enter the ocean. Please be careful in this area.
Aside from the materials a suit is made of, there are variations on the style. Farmer johns are pretty much the same regardless of the source but jackets can come with or without:
- full zippers
- partial zippers
- no zippers
- attached hood
- beaver tail
- step through legs...
Some suits have no farmer johns. Instead they're a full body suit with an entry zipper at the shoulders or across the chest. These suits tend to be more comfortable because only a single layer of neoprene wraps the diver's upper body. The lost warmth in layer thickness is made up for by the fewer entry points for water inherent in the full body suit design. Plus it's easy enough to add a thin neoprene vest for additional warmth.
Each variation is an attempt to compromise between warmth, suit stretch (comfort) and ease of donning/doffing the suit.
In addition to the suit, there are booties, gloves and hoods to consider.
Booties come in either a thick rubber sock style or as boots made out of neoprene with soles that vary from light sneaker to light hiking boot. On the north coast, most divers use boots.
Hoods can be found in 3 mm, 7 mm and 3/4" thicknesses. Most divers use the commonly available 7 mm hood with an attached neck skirt. The neck skirt tucks inside the jacket.
Gloves can be found in anything from 1 mm to 7 mm thicknesses and 5-finger or mitten style. Mittens are warmer than 5-finger but that warmth comes at the cost of having only a thumb and a paw available for underwater tasks. Most common on the north coast are 5 finger 5 mm thick gloves.
I hope this information proves useful. Be safe and be warm.
Last Modified: January 23, 2005
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Daniels
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