Mounting al6 cylinder to the backplate
Pigtail for your cave diving line markers
The BC or wing inflator system consists of the wing's corrugated hose, connected to the wing itself via a plastic elbow, and the low pressure inflator hose, also called an "LPI", connected to a 1st stage regulator.
The corrugated hose can be of varying lengths, depending on the diver's preference. I prefer a shorter length hose of ~12-13", to keep things neat. My LPI hose for a 13" corrugated hose on a doubles wing is ~21". On a singles wing it's probably ~18-20", as the first stage is behind the diver's neck, instead of behind the right shoulder.That seems to be the ideal length for a corrugated hose of that length.
Use proper length hoses to ensure clean hose routing and to avoid having hoses stick out or "up" unnecessarily where they could damage (or be damaged by) the cave or wreck, or entrap the diver. The LPI hose's length should be such that it's not so short that it wants to pull the corrugated hose, allowing it to lay how it wants to naturally, but not so long that the LPI stick up or out, or has a large loop. For more info, see our Doubles Regulator Configuration or Single Tank Regulator Configuration pages.
Additionally, the corrugated hose's elbow should be a simple 90 degree elbow, with no one-way, over-pressure valve, as the valve can be pinched, allowing water to enter the bladder and rendering the bladder unable to hold gas, creating a potentially dangerous buoyancy issue. This page illustrates one method of routing the LPI with the corrugated hose. While it's certainly not the only way, it's a configuration that I prefer after trials and (multiple) errors and hundreds of dives, finally coming to this solution.
Wing (note the simple 90 degre elbow)
2 3/4" pieces of bicycle inner tube
This is probably the most common hose configuration. One where both the corrugated hose and LPI are both routed through a loop of bungee. The bungee is a simple ~2 1/2" loop of 1/4" shock cord. It's held in place by being placed between the harness webbing and the tri-glide that holds the left chest D-ring in place.
Routing the hoses through the bungee ensures the inflator/deflator mechanism always stays in the same position.
Note how the LPI isn't routed cleanly, instead bending away from the corrugated hose, creating a hose routing issue. We'll address this in a bit.
At issue with this configuration is the bungee's ability, and habit, of getting caught in the corrugations. This inconvenience can make it difficult to elevate the deflator sufficiently to dump gas.
Before moving on to the next iteration, let's first address the LPI hose routing. To keep it clean, simply cut a couple of ~3/4" pieces of bicycle inner tube. Place the inflator mechanism through the inner tube, and run the inner tube toward the top of the corrugated hose, near where it connects to the elbow. We'll address the 2nd piece of inner tube later.
Now, simply run the LPI through the inner tube, alongside the corrugated hose. This keeps the hose routing neat and tight.
To prevent the bungee from getting caught between the corrugations on the corrugated hose, I simply ran only the LPI through the bungee. The slick hose allows it to move freely along the bungee, yet both the LPI and corrugated hoses are still held in place by the bungee when not in use.
The issue with the 2nd iteration presented itself on a dive fairly quickly.
The bungee had become lodged where the hose fitting was connected to the inflator nipple. When I raised the mechanism to dump gas, the bungee popped the hose connector off the nipple.
While it was a minor inconvenience reconnecting it with dry gloves, it did happen a second time within a couple of weeks, so it was time to find a new configuration.
To prevent the issues from the 2nd iteration from occurring again, I simply placed a second piece of inner tube on the corrugated hose. Where the first piece is near the top of the hose, I placed the second inner tube down near where the LPI connects to the inflator nipple.
After running the LPI through the bungee, I then run it through the second inner tube. By doing so, the lower inner tube prevents the bungee from working itself down to the hose connection.
The final result is clean and tight hose routing.
Note in the picture below left, the LPI goes through the upper inner tube, then the bungee, then the lower inner tube. This keeps the hose routing clean and tight, while also preventing the bungee from working its way down to the hose connection, while still allowing only the LPI to be run through the bungee, allowing free movement without the bungee getting caught in the hose corrugations.
In order to alleviate squeeze at depth, divers must add gas to their drysuits via a low pressure inflator hose connected to an inflator mechanism on the drysuit.
Often times in recreational diving the drysuit is inflated from the diver's backgas tank(s), which is common practice if air or nitrox is being used.
However, due to helium's thermal properties, if the diver is using a breathing mix containing helium the drysuit must have a separate, independent inflation system.
Drysuit inflation bottles can be mounted on the backgas tanks or the backplate. Typically, 13 or 14cuft bottles are mounted on the backgas tanks, due to their size, and smaller 6cuft bottles are mounted to the backplate.
This page illustrates how to mount the smaller 6cuft bottles to your backplate in the Hogarthian configuration.
If you're using your backgas for drysuit inflation, visit our Doubles Regulator Configuration Page.
When setting up your drysuit inflation mount, it’s important to keep a couple of points in mind;
We have no metal to metal connections. All connections are cutaway, meaning they can be cut by a knife, if needed.
The drysuit bottle is mounted on the left side of the backplate, so as to not interfere with the light canister and long hose routing/deployment and to remain consistent with hose routing when using backgas for drysuit inflation (left post).
Poke 2 holes, approximately 1/4" in diameter, 11 1/4" apart, leaving ~ 3/4" on each side. Burn the holes with a lighter, to prevent fraying.
Tie an overhand loop in the shock cord. Tighten the knot so the loop in the shock cord is ~5 1/4" to 5 1/2" long
Cut the excess shock cord off the end, leaving approximately 1". You may want to put a couple of drops of SuperGlue on the knot as well.
Feed the bungee loop through the bottom hole on the backplate's left side from the back to the front. Then pull the knot through the loop that has passed through the backplate's hole.
Next, pull the knot tight such that the loop cinches down taut against the backplate.
Now it's time to install the inflator bottle.
The drysuit inflation bottle is mounted upside down, to allow the diver access to the valve handwheel on a standard valve.
To mount the bottle, feed the bottom of the bottle through the webbing strap on the backplate. Then, wrap the bungee loop around the valve handwheel, with the loop behind the valve.
The inflation bottle should be rigged so that it doesn't hang below the bottom of the backgas tanks. If it does hang lower than the back-mounted tanks, shorten the bungee loop, as that is what determines the height of the inflator bottle.
The inflator hose is routed from the inflator's 1st stage, under the harness waist strap and connected to the drysuit's inflator mechanism.
When cave diving, we need a way to keep our markers (Arrows, Cookies and REM's) organized and easily accessible.
While there are many methods to achieve this, I prefer to use a simple pigtail, using shock cord. Its simple design makes for easy use and stores the markers nicely.
Thread the shock cord through the boltsnap's eye, with one length ~13" and the other ~7"
Tie a standard loop knot. Ensure one length of the shock cord is considerably longer than the other
Tighten the knot as tight as possible. Put a dab of Superglue on the knot. When the Superglue dries, slide the heat shrink over the knot, with ~3/4" - 1" overlap on each side of the knot.
Heat the shrink wrap with a heat gun or blow drier.
PICTURED LEFT TO RIGHT, BELOW: Step 1, step 2, step 3
Tie an overhand knot at the end of the longer length. Knot to knot should be ~5"
Cut excess bungee from the short end, so it's flush with the heat wrap.
Your pigtail is done. Load your markers onto the pigtail.