|IN MAY I WENT THROUGH A PLETHORA OF CHECKS that, short of having a full dive technicians workshop, can be made to check that a regulator is functioning correctly. |
But what about the rest of our dive kit It all suffers wear and tear while in use. It all seems to dry out when it is stored and to be troublesome when it comes out of the cupboard. While regulators recently serviced, or supposedly so, seem to be the main source of trouble on overseas trips, in my experience it is drysuits that are most likely to ruin a dive.
Failure usually occurs when putting a drysuit on. A seal tears, or a zip breaks, and the dive is aborted before it even starts. At least with most other kit failures you get to start the dive before things go wrong, and you may even struggle all the way through it. It may not be the safest way to dive, but you get to have some fun on the way!
Before moving on to drysuits, however, well start this month with the next hose connected to the regulator, the BC direct feed.
The feed connector to the BC should slide on smoothly
Once on, the feed connector should not leak - its time to get it wet and look for bubbles again
Inspect the crinkly hose for splits
Check the flow of the inflate button
Examine dump valve strings for fraying
The first thing to check is that the direct-feed hose connects smoothly to the BC. It should just slide on and click without being forced. Once on, it should stay there unless the collar is slid back to disconnect it.
If it doesnt connect easily, chances are that the problem is simply dirt and minor corrosion on the surface of the metal. Soaking the connector in warm soapy water, then working the connection on and off a few times, may be all that is needed to get it working smoothly.
But dirt and corrosion are not the only sources of connection problems. BC feed hoses come in several different connector patterns, and even within a particular pattern the tolerances of different manufacturers can lead to a less-than-perfect fit.
Perhaps the hose was replaced during a service, and the new connector is not quite right.
Another problem that often arises from minor incompatibilities between a direct-feed hose and a BC connector nipple is a low flow-rate when the inflate button is pushed. So, with the regulator connected to a cylinder of air, connect the direct-feed hose to the BC, press the button and see how long it takes to fully inflate the BC.
With the BC fully inflated, the next step is to leave it alone and see if it holds pressure. It doesnt have to be perfect, but should last long enough for you to make and enjoy a cup of tea or a cold beer from the fridge.
If you cant be bothered to wait, this can be done while the pressure test is still running. Dip the inflator into the kitchen sink to see if the connection is leaking. Waggle the connection collar about a bit and disconnect/reconnect a few times while it is in the water to ensure that it is sealing reliably.
Inspect each ring of the crinkly hose to see if it is damaged, split or about to split. Obviously, a split crinkly hose will have shown up on the pressure test, but the consequences of a winter in the cupboard may not have shown up yet. It could be on the verge of splitting next time it is taken diving.
As with regulator hoses, quite often any damage to a BC crinkly hose will be close to one of the ends. Length permitting, it can be cut back a couple of centimetres past the damaged part and reconnected.
Have you ever had the BC inflate/deflate end of the crinkly hose, or even the entire hose assembly, come off in your hand
This problem is especially common if the hose has a pull-to-dump mechanism built into the connection between the hose and the jacket. Personally, even on BCs fitted with this gimmick, I never use it.
Whether or not youre in the habit of pulling the hose to dump buoyancy, it may have worked loose. Like a regulator mouthpiece, the cable tie or other attachment clamping it in place could be loose, or it could be on the verge of splitting right at the end. So inspect the end while pulling gently on the hose to make sure it is firmly attached.
Most BCs have two pull-string dump valves, one on the right shoulder and a second above either the right or left hip.
With all pull-string dump valves, inspect the string to check that it is not frayed, especially at the ends where it enters the valve or is attached to the puller. Also look inside the puller and make sure the knot that holds the string in place is not about to pull out through a hole that has worn and enlarged since the knot was first tied.
If a dump valve leaks, it could be because the mechanism is jamming, or because the valve mushroom or seal inside is dislodged or damaged.
These dump valves frequently double as over-pressure valves, so inflating the BC fully and beyond should cause one or more dump valves to blow.
It is quite easy to go a whole year without actually puffing any air into a BC via the oral inflate. On the other hand, the same button at the end of the crinkly hose is often used for dumping buoyancy.
Blowing into the oral inflate, check that exhaled air is actually going into the BC and not leaking out round the button. Release the button and confirm that the oral inflate closes, the BC holds air and does not leak back out again.
With the BC fully inflated, press the dump button on the oral inflate and gently squash the BC. Confirm that deflation is not constrained by an improperly opening button.
Whether or not you carry out any of the above tests, the most important part of checking that a BC and regulator are working is to take the whole set-up into the pool for a test dive in a nice safe environment.
The feed connector to the drysuit should slide on smoothly
Checking the flow of the inflate button
Examine the seals for nicks and splits
Examine the zip for broken teeth
This seam is starting to come undone
Check boot fabric for nicks and splits
The drysuit inflator and hose can be given the same tests as the BC inflator and hose. Check the connect/disconnect, check for leaks, make sure that adequate flow is achieved when the button is pressed, and see that it closes fully when released. Also check that the inflator and dump valves are firmly screwed into the suit.
Dump valves need to be checked to ensure that they allow air out when they are supposed to and will not allow water in. Whether it is a cuff dump or a shoulder dump, a simple test is to snog the valve from the inside of the suit, blowing to check that air can get out, then sucking to make sure the valve seals effectively and water will not get back in.
Visually check drysuit seals for tears and punctures. On latex seals, look for crazing that could soon develop into a tear, for nicks in the edges of seals that will act as a focus for a later tear, and for gooey areas that indicate that the latex is well past its use-by date.
Gently bend the drysuit zip to make a visual check for breaks between the teeth. Also look for frayed edges that could foul the zip when it is closed. Run the zip up and down a few times to check that it works smoothly, and lubricate it as a matter of course.
The seams of a drysuit need to be checked inside and out. Where a seam is stitched, look for frayed stitching that is starting to unravel. Where a seam is glued, look for areas where the glued parts are beginning to split apart. Where a seam is taped, look for areas where the tape is peeling or damaged.
The latter is particularly important on membrane suits that have been stitched through during manufacture. In general, the only thing that stops such suits from leaking through 10,000 tiny perforations is the integrity of the neoprene tape applied across the inside of the seams.
Where suspect areas are found, the appropriate repairs to stitch, re-glue and/or patch are best carried out while the suit is bone-dry, rather than hurriedly drying it after a wet dive to enable repairs.
While many potential drysuit leaks can be found by careful visual inspection, there can always be pin-prick leaks that can be located only by a more rigorous test.
The best leak test for a drysuit is to block the wrists with jam jars, block the neck with a football or bowl, inflate it to Michelin Man proportions, then sponge it with soapy water to look for bubbles.
Its not only drysuit seams that can be the source of leaks.
Any cut, gouge or area of worn material can indicate a leak in waiting for the new season.
So inspect the whole surface of the suit inside and out, making repairs where necessary.
The basic plain rubber drysuit boots can craze and split in the same way as a seal can, so look over them carefully for any surface damage that could turn into a leak when the suit is used.
On neoprene boots, look for areas where the nylon lining is damaged or beginning to de-laminate, both inside and out. On an older neoprene suit, some damage to the nylon can be expected, but boots take a lot of wear and tear, so more caution needs to be taken in deciding whether damaged drysuit boots can be taken diving.
Examine straps for nicks that could fail when stretched
Clean, inspect and grease O-rings
On anything electrical such as computers and dive lights, I tend to find it hard to remember whether I ended the last season with good batteries, or if they were almost out.
The wonderful battery level indicators on some dive computers dont help: 99%, 98%, then straight to fail seems to be the norm. Whatever happened to all those levels between 97% and 1%
So wherever a battery is user-changeable, I like to pop it out and test it with a voltmeter to see just how good it is.
Of course, I need to know the value to which to compare it, so it helps to have a new battery available to measure for a good value, and a previously discarded battery to measure for a bad value.
While batteries are out, all O-ring grooves should be cleaned with a cotton bud or soft cloth, then inspected to make sure that no stray fibres have been left behind.
O-rings can be washed in warm soapy water to remove dirt and old grease, then visually inspected for damage. As a final check, licking an O-ring can identify remaining dirt or damage, as the end of the tongue is sensitive to the smallest imperfection.
Then re-grease O-rings with the lightest coat of silicone grease, or other grease where the manufacturer recommends anything other than silicone.
Youre sitting on the boat, everything working fine, buddy check completed, ready to roll over the side. You pull your mask on and the strap breaks. Or perhaps its a fin. Its amazing how items as simple as a strap can spoil a dive.
On any rubber or plastic strap, stretch it slightly and look for nicks that could develop into tears. Also inspect the ends where straps are threaded into mask or fins. Are they properly threaded Are the buckles intact and properly fitted
KEEP UP TO DATE WITH EQUIPMENT SERVICING
I know that quite a few of the examples I have used over these two articles have involved sub-standard servicing. But dont let that put you off keeping up with the service and maintenance schedule for your diving equipment.
The vast majority of equipment will come back from servicing working as well as it did when it was new. The checks described can be used to verify that servicing quality has been met, and if it hasnt, you have the chance to take the equipment back before your next trip is spoiled.