How Much Weight?

The question is usually quite simple. When a diver checks in at the dive center they are asked, “How much weight do you need?” The answers though, run the gamut. Some divers know exactly what they need and keep a record, which is a good idea because it certainly can save a dive. Others don’t have a clue and their answers are more like the following:

  • “I don’t know!” This is the simplest answer. Sometimes this is because it is a diver’s first experience in different conditions. The diver may have done all certifying dives in a quarry in the spring and now this is their first tropical dive with less wetsuit. But too many just don’t know, even though they dive year after year at the same place.
  • “I use 3 of them.” One of my personal favorite answers. Since 3 of “them” could be anywhere from 3 pounds to 18 or more, it does not help the person trying to assist in getting weights.
  • “They are the square ones.” This answer is usually a follow-up from # 2 when trying to determine more accurately the amount.
  • “Same as last year.” As if every resort operator or divemaster remembers everyone’s needs.
  • “32”! An answer like this usually provokes another question, if the diver is in the tropics, such as “Is that what you wear at home?”, which usually turns on a light and the diver suddenly realizes they are diving in a skin only.
  • “I don’t know. What do you think?” You don’t want to know what I think.
  • “Oh, 10 to 15 pounds.” There is a 50 % increase from 10 to 15! Also, that leaves 11, 12, 13 and 14 as options. Not a good answer.

The whole point is that weighting is very important. It is a major aspect of a diver’s training and therefore should be a major part of a diver’s preparedness. The old 10% rule which says start at 10% of your body weight is too broad. First of all, does this mean in fresh or salt water? Does it mean a dive skin, a 3 mm shorty wetsuit or a full 6 mm farmer john and jacket, hood, boots, and gloves? These are just a few of many variables in weighting oneself.

So where do you start if this is your first dive under different conditions? Try asking your instructor or the divemaster for suggestions. Or if a swimming pool is available, practice with some various sized leads close by so adjustments can be made. Always have on the same equipment you will be using at your dive. Remember to add some extra for salt water.

After all is said and done, the most important thing is that once you are satisfied with your weighting, write it down somewhere. A logbook is the obvious place. Many have an area for this. Keep a record of where you were diving and what equipment was worn. Now you will always have a starting point from where you can improve your skills. It will make your first dive of the season or vacation that much more fun. You’ll also impress your divemaster.

Bruce Bowker


Once, when looking through a dive company’s catalog, I noticed the descriptions of the many fins they had for sale. One description said, “triple vented for maximum power.” Another fin was described as “unvented for greatest force”, or something close to that. How can a fin with vents be maximum and one without be greatest? I decided to see what other catalogs said.

Fin Comparisons

One fin claimed best optimization while in the same catalog a different fin was fully optimized for best results. Another manufacturer said that a particular fin was the world’s most popular (not quite sure how one establishes that). Yet another fin claimed, because of channeling, it worked on both up and down strokes. I have tried to get a fin efficient on the upstroke for years and it just is not even close to the power on the down. Try it sometime. The upstroke even tends to slow you down!

Some companies have 7 or 8 fins in their catalog each claiming to be the best. Then there is the fin designed for the economical diver but still giving total performance without losing quality, and at only $49,-. Maybe that’s the price for just one fin. Why would I want to spend $149,- if the $49,- pair gives “total” performance and quality construction? Marketing!

Another fin was supposed to stop side slip, a most important thing underwater. Once when I was admittedly exceeding all underwater speed limits, I saw a coral head coming up very fast and tried to swerve hard to the left. The side slip sent me crashing head over heels into a bank. That side slip! I am glad there were no underwater police who saw this. I didn’t file a report either. The fin also had maximum water displacement. Maximum compared to what?

A Persons Technique Is Key To Better Performance

I have always liked those tiny little inky binky fins called stabilizers on top and in some cases on the bottom of the blade. Cute little things but are they worth anything except a few dollars more to the cost? Maybe if they looked like a ’57 Chevy or how about a ’59 Caddy – night ID lights and all…! I have used fins without them, with them on top, bottom, top and bottom and have found absolutely no noticeable difference whatsoever. It is the person using the fin, not the fin. I didn’t spin in circles nor rock myself to sleep without them.

There used to be a pair of fins with 3 vents and little flaps that covered the vents so on the downstroke (the power stroke) the vents opened and on the useless upstroke they closed. There was some great engineering! Another company had covered channels, pipes so to speak, running the length of their fin blade. No idea what they were supposed to do but I am sure someone came up with an answer to market them. They also had those little fins on top and bottom. And what about triple battened, graphite reinforced Kevlar killer fins? It’s still all in the user.

It seems fins are going the same way sneakers did many years ago. Remember when you just bought a pair of Converse All Stars or even a pair of Keds? Now there is a sneaker, I’m sorry, an athletic shoe, “designed” for anything anyone could hope to do. Whoever comes up the wildest looking pair with all kinds of different color inserts and doodads sells the best. There are now fins with movable pieces of plastic, weird shapes, slots and slits, holes, and buttons and on and on. Yes, marketing has certainly taken over practicality and what really works.

Perhaps the most interesting description was a fin with concave side ribs which controlled rocking motion (I guess we would all get seasick otherwise) by allowing the vector flow of channeled force to be displaced equally along a longitudinal cross margin of the resistant hydro-dynamic ratio, at least that is the way I understood it. If none of that makes sense, then the formula of how it is established obviously will. 4X(bc-3y) + 2a + b + c = Force Area Kinetic Energy, known as FAKE in the professional circles. See it really is simple and I am sure your fin kicking has just improved dramatically.

Marketing Strategies

At a dive show, one manufacturer had a tank of water with a really cool looking aluminum mechanical leg, lots of tubes and struts, which was powered by air or something. It hissed and moved up and down and water moved around and all kinds of great things, thus proving that particular fin to be the best there was. But was the user? I asked if I could have my legs replaced by two of those aluminum babies, but they said it would cost too much. I really wanted to have the best fins on the best legs. Just think, no muscle cramps.

Now the latest marketing strategy says there is a fin that acts like a propeller on a boat. Sorry but there just isn’t any way the physics of a propeller can be remotely compared to that of a dive fin on a human being. These are two completely different things. An article in one of the outdoor type magazines proved how great these fins were by telling the story of 4 divers, one of which was an experienced diver and a green beret. All four saw a manta ray but only the three with the super fins could keep up while the green beret fell behind. Nothing was mentioned if the green beret was 75 years old and 200 pounds overweight. Don’t trust the word “experienced” either. If I have two dives and you have one than I am twice as experienced as you are. Marketing!

There is an advertisement for a super dooper fin which has something or other on it to end ankle torsion. What the heck is ankle torsion? Torsion is defined as the twisting or wrenching of a body by the exertion of forces tending to turn one end or part about a longitudinal axis while the other is held fast or turned in the opposite direction. So, if you are wondering why, you and every other diver, at the end of the dive, have your feet on backwards, this is why. Personally, I can only walk backwards now because of years of ankle torsion while diving!! A 5000-horsepower dragster has torison as it tries to twist the frame in circles – but divers? Somehow, I get the idea that we are all supposed to be able to swim at around 135 mph underwater or kick at 250 udpm (up down per minute).

Some companies try to market scuba fins and snorkeling fins as different things. For that reason, many people new in the sport think fins with closed heels are for snorkeling and those with straps are for scuba only. I guess I have been snorkeling with a tank on my back at great depths now for a few decades. There just isn’t such a thing as a purely snorkeling or diving fin (same goes for masks.)

Fin Choice Is A Subjective Topic

Seriously, the best fins I ever wore were the cheapest that one company sold. It wasn’t that the fin was far superior to any other fin. The main thing was I was used to them, wore them enough that I got to know exactly how to get the most efficiency from them. Eventually they tore from use, and I went to a different fin, my old style no longer being made. I had to start all over again getting the best efficiency from the new fins. And they did require a slightly different kick.

Fin choice is very subjective. I had a diver come into my shop, pick up a pair of fins, gave them a once over and said they were way to flimsy in the blade. 30 minutes later an unrelated diver came in, picked up the same pair and said they were way too stiff! I always thought they were sort of in between!

For me, it isn’t as much the fin design as the person who is using them. The “best” fin in the world isn’t worth a nickel if the person using them can’t kick. I watched one diver, with knees bent nearly 90 degrees, fins back at another 90 degrees, push their legs back and forth, more or less using the thin leading edge of the blade as the area for propulsion. Cheap fins or $200,- fins, that diver simply could not kick, and no fin would improve it.

Think of a fin as a large paint brush. Like painting, only the end of the fin, let’s say maybe 5 inches or so, is where the most power comes from. Think of a barn door behind you and you want to get good coverage with the fin. Nice straight strokes up and down. Just like painting. The brush is always on the work. Don’t try to cover a 6 ft. stroke with each kick. Just a nice up and down motion. Keep experimenting. Maybe a slight flex in the knee. Maybe a different angle at the ankle. Maybe both. I now have my kick to where, under normal conditions, I just roll one ankle of one foot. I can move along as well as some who are kicking like a mad horse. It is all practice, trial and getting more efficiency. It is easy. You just have to give some thought as to what is happening at the end of your feet.

Although it is not possible to watch yourself kick, you could have someone video you and watch that. You can certainly watch all the other divers and see what they are doing. And you will see many different uses of fins. Some bad, some good. Look and learn. Squeak out just a tad more efficiency each time. Make sure when choosing a fin, marketing hasn’t outranked technology. No matter what a manufacturer claims, there is no machine which measures force, displacement, thrust, power, decrease in air consumption and so on and so on. Testing is done mostly by humans and therefore both highly subjective and variable.

Bruce Bowker

Well Balanced (physical, not mental)

Next time you are on a dive boat or with a group of divers take a close look at what they are Next time you are on a dive boat or with a group of divers take a close look at what they are wearing, especially if you are in the tropics. Are they all dressed the same? Do they all look the same? From my experience, the range runs from just a bathing suit to a full 1/4-inch farmer John, with bodies that are thin, heavy or all muscle.

Why do divers wear weights in the same place?

If divers all have different equipment, dive suits and body builds, how can they all wear weights in the same place? Think about this for one minute. One diver is wearing a dive skin, another has a short-sleeved shorty with high cut legs. Another diver is wearing just the farmer john part of their suit and not a jacket. Another diver has on a long sleeve 1/4-inch jacket only. Some BCD’s are negative while others have a tendency to float. No two divers are alike, yet all wear their weights pretty much in the same place.

Look at a fish. How does it swim? Horizontal in the water. Yes, trumpet fish stand on their heads, but they are not swimming! Fish are balanced, divers are not. The heavier part of a diver’s body is usually the legs. The lighter part is the chest area where the lungs are. So where do we put weight? At the heavier part. Where do we put air? At the lighter part. None of that makes sense. Basically, all of the dive equipment is saying “Stand up in the water.” Not only that but the tank located on the back tends to make a diver roll over on their back. There is no balance here at all.

Some divers are foot light, but a vast majority of divers are foot heavy to varying degrees. This means that when a diver stops kicking the feet tend to drop. In some cases, a diver’s normal swimming angle can be up to and in extreme cases more than a 45-degree angle to horizontal. This is not only uncomfortable but very inefficient. Inefficiency means more work. More work means breathing more and more breathing means more work to stay down. This turns into a loop which most people solve by adding weight. This increases the foot heavy problem, and the cycle continues.

Divers who are foot light have a solution, ankle weights. But what do foot heavy divers do? No one has really marketed anything to solve this problem. There is a buoyancy video that very clearly shows that swimming horizontally is correct and foot heavy or foot light is bad. If you are foot light it says use ankle weights and stops there. It says absolutely nothing about foot heavy. What do foot heavy divers do?

The solution is to add weights towards the top of the diver. I wear 12 pounds of lead with a 1/4 jumpsuit, and I am very foot heavy. Or as some would like to say, an air head. Regardless, my weight configuration is 6 pounds at my waist and 6 pounds toward the top of my tank. With this set up, I am horizontal in the water. To go down I simply swim down and to go up, swim up. Almost all the kicking power is used efficiently. Foot heavy divers tend to kick themselves toward the surface. Their answer? More lead?

Foot heavy divers also have great problems swimming in any kind of current, from mild to Foot heavy divers also have great problems swimming in any kind of current, from mild too strong. Think of an airplane which is flying along happily. Now bend that wing up and what happens? The plane goes up. The pilot can counter this with trim tabs, but the efficiency drops. Pilots also load planes for best balance. Divers just put weight around their waist with no thought to balance.

Balance is different from weight

A diver who is correctly weighted and balanced with 6 pounds on the waist and 6 pounds at the top would also be correctly balanced with 10 at the waist and 10 on top but not correctly weighted. Make sure you make a clear distinction between these two.

One can get into numerous formulas of weight distribution over the cross vector of air control flow factors divided by depths of compression volume with force equal to the division of the equation of nonsense, but fish don’t do that so why should we? Next time you are in the water try a simple experiment. Go down to about 20 feet and simply try to lie horizontally in the water. Absolutely no air can be in your BCD. Absolutely none, zero, zilch, zip. Why? Because how much is in it? The same as yesterday? The same as tomorrow? This experiment must have a constant and that can only be with an empty BCD. Don’t kick or try to do anything. Just see what your body does. This may take a few seconds, so wait. If you are foot light, then ankle weights might help. If you are foot heavy, then weights must be added somewhere else.

A short weight belt with one lead weight on each side placed between the tank and backpack, above the tank band, works very well (and it is cheap!). Some packs with twin bands have problems as do soft packs. Some ingenuity is required to see what your particular BCD will allow to work. Ideally it would be great to have either a BCD or a wetsuit top with many small pockets all over the top (front and back) where weights could be placed to accommodate each individual’s equipment and body build. As this isn’t the case a short weight belt is a start. One diver, as an experiment wore a weight belt up under the armpits. Just an experiment, but it helped! Weights in the top back of the BCD do not help the roll over problem but for whatever reason this has not affected my diving. Others have said they can feel this weight trying to roll them over. Again, this is a start. Until someone makes extra weight pockets all over the place there aren’t too many options.

Dropping weights in an emergency

Now the big argument. How does one drop the weights in an emergency? First, and most important, weights have only one function for most recreational diving. That is to make a diver as close to neutral as possible. Weight should not plunk you to the bottom and then put air in the BCD to lift you up. It’s right back to the first problem of weight on the bottom and air on the top.

There are counterarguments. It is unusual for someone to have all their lead on the top. If weights have to be dropped then those around the waist can be dropped. No, you don’t go head heavy. There are divers who wear no lead at all. How does someone who wears no lead drop a weight belt? If two divers are very well weighted and balanced, one with lead and one without, both can swim to the surface with virtually the same effort or lack of effort. Divers who are overweighted have to work to get up or drop belts.

Wetsuit compression

Other complaints are about wetsuit compression. Wetsuits do compress but not to such a tremendous degree that 30 pounds are needed at the surface and half a BCD full of air is required at 60 feet. That is a bit of an exaggeration, but the point is there. Obviously full 1/4 farmer John will be quite different from a 1/8th inch shorty. Still compression is not so severe. I find with a 1/4-inch jumpsuit that through kicking a bit differently, breathing a bit differently, I can control this to most acceptable depths. Some have argued than changing your breathing is bad. Don’t we change our breathing all day long? Walk up the stairs and see what happens. Have someone scare you. I’m not talking about hyperventilating underwater or holding breath, just relaxing more.

Most divers complain about an area from the surface to about 15 feet of water. This “problem zone”, as I call it, is where divers have trouble getting down at the beginning of a dive and staying there at the end. For most divers’ extra lead is the answer. Unfortunately, this creates balance problems for the vast majority of the dive. Why be correctly weighted for a few minutes and out of balance for an hour or so? To get through the problem zone at the beginning of a dive it is critical that no air is in the BCD. A good strong surface dive can put divers deep enough underwater that a few kicks will propel them past the problem zone.

Old versus new BCD’s

Something else should be looked at now. Many older BCD’s have hollow hard packs. These packs hold air. Most have two tiny holes in the bottom to drain water. Heaven forbid anyone would want to get a dive boat wet. The only way to get air out is to stand on your head. The holes are too small so you may be standing there for quite some time. Drill these two bottom holes to at least a 1/2-inch diameter. Also drill two large holes at the top in the handle. Some packs have solid handles so look at yours. If so, find the highest point possible and drill one hole on each side. One manufacturer was clever enough to put a small hole almost at the top but on the inside, so it is restricted by the divers back. Many BCD backpacks are now made with holes top and bottom, but these should be much larger. The air should get out instantly. Many who have drilled out their packs have taken off two pounds of lead. Think about that. They were wearing two pounds of lead for the first few seconds of the dive. After the pack emptied, they carried two pounds of unnecessary lead. Many of the newer BCD’s now have a plate for a backpack and no air gets trapped at all.

Carrying unnecessary lead is like going shopping with $100 in pennies in your pocket. It makes you tired carrying it around. When you get tired you have to work harder to get things done. Work means breathing more which means floating more. The more you float the harder you have to work and once again a vicious cycle begins.

Are you floating upwards?

The next part of the problem occurs when divers get back near the problem zone at the end of the dive. Here the main complaint is tanks getting lighter. Tanks do get lighter but only one breath at a time lighter. It is always interesting to hear someone say, “When my tank hits 1000 psi I shoot to the surface.” Are they saying that at 1001 psi they can stay down? Something is wrong here. My suspicions are twofold. First anyone who is naturally foot heavy tends to kick to the surface as already discussed. Compound this with a slightly lighter tank and shallower water, many divers simply kick to the surface. Second, many still have air in the BCD adding to the problem.

Try another experiment. When in shallow water just stop. Do your feet sink? For many this sends a signal to their brain that they must be floating towards the surface. If their feet are sinking, then their head is shallower than their feet. They aren’t getting shallower, but they think they are. The immediate reaction is to try to kick back down. Try kicking to get down when your head is pointing up. Also not wanting to “float” to the surface can put a bit of adrenaline in the system which makes one breathe more and here we go again.

Relation between fins and buoyancy

Use of fins, as trivial as it may sound, is related to buoyancy more than one may think. The more efficient a kick the less work, the less work, the less breathing and so on. Watch other divers underwater. See how they kick. Is it efficient? Are they moving along effortlessly or kicking like crazy and hardly moving? Almost everything one does underwater is related to buoyancy. The less efficient a diver is the more they breathe. Here we go again. The more they breathe the more they float…!!!

This is just a small sampling of what can be done and a few options to try. Some things work great for some divers and other things for other divers. Without experimenting though, one would never progress.

Bruce Bowker

The BCD Wars

At some point, I can’t quite remember when, someone, somewhere decided to have a BCD war. Mine is bigger than yours so mine is better. The next day his was bigger than mine and so on until we all arrived at BCD’s with some amazing and ridiculous amount of lift. This war spilled over to the general diving community and people were told the more lift the better the BCD. Manufacturers made bigger BCD’s and then, through marketing, told everyone they needed them.

Are Heavier BCD’s Necessary?

Being a diver who has spent time in both cold (under ice) and tropical waters, my observations are far from limited to one area of diving. I had a discussion once with a diver who did most of his diving on North Atlantic wrecks. He was in one of my buoyancy classes and made it very clear that my ideas probably worked well in warm water but for his type of diving a BCD with 65 pounds or more of lift (that’s what he said!) was necessary. Asking why, he explained because of the heavier equipment worn and heavier wetsuits. He also explained that his kind of diving used twin steel 90’s or 120’s and with all that weight, plus 2 heavy knives, lights that sink plus a few other odds and ends and X pounds of lead, 65 plus pounds of lift was necessary.

Let’s examine this a bit closer. Are these divers with all this heavy equipment, which is apparently already dragging them down, wearing additional lead on a belt? If so, why? If I put weight on my back (e.g. heavy tanks) then some amount would come off the weight belt. If I leave my knives and lights home, perhaps use an aluminum tank, then I would add some lead. But to add both weighty equipment and then lead to the belt is counterproductive.

One of the primary objectives of good diving is to get as neutral as possible. Pure neutrality is quite impossible though, because of numerous factors such as breathing, wetsuit compression/expansion and the tank gets lighter with each breath taken. But getting close is what a good diver strives towards. With that in mind, why would someone make themselves so negative that they would need 65 pounds of lift? Or even 50 or 30 for that matter. The only explanation would be, for example, a diver who actually needs 28 pounds of lead but wears 58, so a BCD with at least 30 pounds lift would be needed just to get neutral.

Wetsuit compression

Wetsuit compression always enters into any discussion about cold water BCD’s versus tropical. This is pointed out quickly in any argument for those who wear oodles of lead with inflatable boats strapped to their backs. Wetsuits do compress but not to the degree that the kind of lift some claim is necessary. Again, I wear a heavy wetsuit (I have even worn a full hooded farmer john in tropical water) as do some of my staff, and none of us, no matter what depth (even very deep) have any trouble with buoyancy. Nor do we put air in our BCD’s to compensate. I can see the reason some people do need to overcompensate with a BCD. They are so overweighted that they would be walking on the bottom. Instead, they inflate the BCD and more or less walk through the water because of all the air lifting them at the top. So where is the argument about wetsuits?

A friend of mine completed his second diving expedition to Antarctica. He wore a total of 50 pounds of lead. No BCD’s were worn at all. The 50 pounds made him “neutral.” No need for 65-pound lift BCD’s. And that has got to be some of the most extreme diving there is.

There was an article in a well-known dive magazine which was about selecting a BCD. It said something to the effect that one should choose a BCD with 10 or so pounds more lift than the total weight worn. As an example, it said a diver who wears 30 pounds of weight should have BCD with at least 40 pounds of lift. I read this twice to make sure I understood and wondered why a diver would wear 30 pounds if it made him 30 pounds negative? 30 pounds should make him close to neutral negating the lead. So, a BCD with just a little lift would be fine.

Why I never put air in my BCD underwater

I never put air in my BCD underwater. I use my BCD for 3 reasons only. One, it is great way to keep a tank on my back. Two, it meets a requirement of not diving without one and three, the most important, it makes a great surface flotation device. And that is what it should be, an SFD. A true buoyancy compensation device would be designed completely differently.

Generally speaking, the less buoyant part of our body is from the waist down. Where do we put weight? On the waist. The more buoyant part of our body is from the waist up, the lungs. Where do we put air for buoyancy compensation? At the top. Because of the design of a BCD this air is always at the highest point. Our equipment is making us stand up in the water. It is all backwards.

This makes many divers foot heavy. In being foot heavy the diver’s angle to the water is always in a “head pointing up” manner. This can also be referred to as “air head” but foot heavy sounds nicer. This angle can be slight, or I have seen in many cases quite severe. Every time a diver kicks, part of that force is propelling the diver up and part forward. Part up, part forward. A very inefficient kick. To keep from going up with each kick, a diver must add weight. Where does that weight go? Around the waist making the diver even more foot heavy, compounding the problem. Inefficiency usually means breathing more. More air in and out of the lungs makes a diver float more, compounding the problem. If you float you add more lead and on and on, we go…

Not one BCD on the market is correct

Not one BCD on the market is correct. I don’t need 20, 30 or 40 pounds of buoyancy control. A diver should not need more than a few pounds of control. Because manufacturers always like to make things enough for everyone, I would say 8 pounds of control is an awful lot but let’s use that for the sake of discussion. Any more than 8 pounds of lift and I highly suggest taking that much lead off and emptying the BCD. Why would I want 8 pounds of air in my BCD and add 8 pounds of lead to equal the air when I can get rid of the air and the lead?

Where should this 8 pounds of buoyancy control be? Definitely not at the neck. This lifts a person up at the head creating a very bad swimming angle. This is what every single BCD on the market does. Not at the feet which is impractical and lifts the feet up. The only place is in the middle which balances the diver. This cannot be in front (on the stomach) as it would flip the diver over. Years ago, one manufacturer had a horse collar BCD with both bottom and top flotation. The idea was there but done all wrong. The place for an 8-pound bladder would be at the bottom of the BCD and at the back.

There are some arguments against this. Yes, it would need a separate inflator – one that is very restricted so it would inflate very slowly. The actual partitioning of an existing BCD should not be too hard as all that has to be done is ultrasonically seal it. A simple manual dump valve could be installed since it is an easy place to reach. Another argument was that it would require another inflator, more hoses etc. This can be worked out as either a separate hose or incorporating the current one to do two jobs. Many got upset when the auto inflator first arrived. “All of them there extra hoses!!” Hoses became accepted but it took how many years to finally get rid of CO 2 cartridges and thank you for getting rid of them.

BCD’s have come a long way since horse collars, which still have a use in certain places. But BCD’s have been mostly marketed and not designed to a diver’s needs. The current rash of BCD’s designed especially for women also leave a bit to be desired. Only a few are really designed for women. The rest, well, just marketed as such.

Too many divers are sold a BCD that is much too large

I am sure I would be sold a large and if I told the store salesperson, I was wearing a 6mm wetsuit, I would be forced to try even an extra-large. A salesman was in my store recently with a sample of a “woman’s” BCD. It fit me well and it was supposed to be a woman’s small! I am sure if I had been in someone else’s shop, I would not be allowed to buy something that small even though it was a great fit. “You need bigger especially if you are wearing a wetsuit.” When I think of how much “bigger” a wetsuit makes me, it just isn’t much. I certainly don’t look like the Michelin man when I wear it so why do I need a BCD 2 sizes larger than what fits me? I guess I just need all that lift! Ah, the BCD wars.

Bruce Bowker

How to Fit a Snorkel or Scuba Mask

Mask Advice from Bruce Bowker

How many times have you gone into a dive store, tried a mask that seemed to fit just great, got on an airplane to halfway around the world, jumped into the water and the mask leaked? There seems to be a nearly universal way to try a mask, which unfortunately happens to be the wrong way. Put the mask on, inhale through your nose and guess what? The mask fits. Right? Wrong!

The big mistake is that no one dives or snorkels with a vacuum in their mask or shouldn’t be if they are. By inhaling through the nose, an unnatural seal is created. Some divers have tried on masks that don’t even come close to fitting but as soon as they inhale, a tight seal is created. While diving though, they are not constantly trying to inhale through their nose (which is what the store clerk told them to do) and now the mask leaks.

Someone told a tale of a dive store that displays all masks without straps. The idea apparently is to check that a really good vacuum makes a really good fit. Once again, no one dives trying to inhale through their nose constantly and without a strap no less.

Insuring a Good Scuba Mask Fit

Almost all modern masks have an outer seal and a narrower inner seal. This inside seal covers everywhere except just under the nose. If both of these seals touch the face than the odds of that mask fitting and not leaking are very good. This is done by putting the mask on with the strap loose, but in place, and then tightening it to what would be normal if you were diving. Some divers who have had very bad masks are in the habit of over tightening the strap on a new mask in hopes of a better seal. Don’t do that especially while trying masks for fit.

The next step takes a second person or a mirror. Look around the entire inside of the mask checking to see that the inner seal touches everywhere. It is very important not to inhale through the nose which forces the mask seals to touch if they didn’t naturally. Next check the outside seal the same way.

If the inner seal is not touching the face, especially next to the side of the eyes, it is likely the mask won’t work well. But do check everywhere around the inside. The outer seal might keep water from dripping in but not as well as if both seals touch. Make sure the seals do not cut across any hairline or eyebrows. Also that the side seals are not right at the edge of the eye.

What if my Scuba Mask Leaks Under the Nose?

One other problem can occur when someone laughs, smiles or even squints. This motion creates lines or wrinkles next to the nose. Sometimes this makes a passage where water pours in. Almost every mask will leak when this happens. So don’t laugh! Occasionally, depending on the person, these wrinkles may remain even after they stop laughing. In this case it may be necessary to straighten the face by pulling down or sideways on the cheeks. Again this is not necessarily a mask problem. So don’t run out and buy a new mask.

If absolutely necessary, to keep everyone happy, you can now inhale slightly to check any unseen leaks. Sometimes a mask leaks around the glass. This is very unusual and is a one off problem, not the design of the mask. You can check this by holding the mask with the face plate parallel to the floor and putting water in the mask. If the face plate seal is faulty, drops of water will appear on the outside.

Don’t be fooled by the size of a mask’s frame and lenses. This has little if anything to do with how a masks fits. People will look for what seems like a narrow or wide mask, depending, but what counts is the size of the skirt where your face is actually touching the mask. An exaggerated example but if the lens of a mask is 1 foot wide but the skirt is only 4 inches, this would fit a rather narrow face but the mask looks huge.

With literally tens of dozens of masks on the market, there is one that will fit. It may take awhile to find but it is out there.

Bruce Bowker