How Do These Bungees Secure The Tank?

[DA Aquamaster]

If it's meant to be a loop-style bungee, then the boltsnap and quick-link are really going to complicate matters around the cylinder. They'll catch, slide, jam and wedge... nasty.

There's really no need for the quick link at all...or even the bolt-snap (for a loop bungee). Most attach directly to the shoulder harness, by way of a triglide/knot or a floating loop on the webbing.

The only common bungee system that requires a quick-link is the (DiveRite) Ring Bungee. But this isn't a ring bungee.

To me, it looks like a frankenstein mash between a loop and ring bungee. Achieving neither of the benefits of either.

If the diver can easily reach the loop without it, the boltsnap and quicklink are not needed. On the other hand, if the bungee is hard to find or reach, then having either a bolt snap and a quick link, or a loop of paracord to a quicklink to connect the loop to a shoulder D-ring can help a lot. Properly configured, the bungee will slide through the quicklink and function normally. The only time it's a problem is if the paracord or boltsnap is too short and pulls the loop forward.

 

[Reku]

I've got these super awesome L/R handed valves with extended posts and and isolate ports (plugged them) - they work great for sm.

 

[BeijaFlor]

Razorista, thanks for posting the video on page 1, and extra thanks to Steve Martin for making it ... I'm getting ready to trade up from my old DiveRite Transpac II and Trek Wings (with Nomad ring-bungees); as of now the Hollis Katana looks like my best bet, and tit uses loop bungees. This was exactly the reminder I needed.

(Incidentally, I don't dive around home, just on tropical holidays, and that means I'm using the dive boat's aluminum tanks; so I have to take that into account with my new setup.)

 

[kr2y5]

I've recently learned that some of the cold water rigs were not designed to work with the loop-around-extension post method, which is what Steve Martin shows in his videos, and indeed I haven't been able to make it work so far with my Halcyon Contour. FWIW, here's how I'm attaching mine, just looping around the valve knobs. Bungee highlighted in red and yellow.

 

[DevonDiver]

Isn't that 'double' bungee problematic?

I assume that you're bungeeing the primaries first. That'd mean the stages/deco would be bungeed over the top of the primaries. If you then partially detached the primaries and swung them forwards, it'd create some twisting pressures on the stage/deco bungees. I'd predict it might push the bungee off the handles?

Also, what is the issue with not getting loop bungess to work on a Contour? I've put loop bungees on every rig I own, or have trialled, thus far. I've never seen an issue, as long as you have some grommits or a D-ring at the back. It should be set-up so that the bungees runs hortizontal back to chest... but that's normally a factor of rig adjustment. On the photo (above) it's a little low... should be more snug under the armpits.

 

[kr2y5]

Isn't that 'double' bungee problematic?

To be honest, the added clutter does bother me a little, but I can live with it, and without the second bungee, the deco bottles do not stay as snug against my chest as I would like. Below is how my bottles are rigged, and how they hang when taken off the second bungee. Making top attachment shorter than this means it's crushing my finger in a dry glove as I try to loop it through to manipulate the bottle. I use the large ring bolt snaps from Extreme Exposure, these work the best for me. Given the length of the bolt snap, plus the size of the D-ring, I cannot see how it could be made more snug against the chest without adding the second bungee. Always grateful for suggestions, though. In my current setup, the second bungee serves to pull the front of the bottle a little towards my chest, as well as to pull it slightly backwards towards my legs (for that reason, I'm routing the second bungee behind the main tank valve).

Bottle

• kr2y5
• Jul 31, 2016

Off-bottle-bungee

• kr2y5
• Jul 31, 2016

I assume that you're bungeeing the primaries first.

Yes, here's my donning sequence (the doffing sequence is the opposite). I find it necessary to remove the main tank off bungee in order to put the lower bottle attachment on the rail or take it off, otherwise the tank is crushing my hand and I cannot manage to squeeze it through (it can be a function of my lower attachment on main tanks, which are 0-length right now). I seem to need the extra clearance.

- attach main tank bottom
- attach main tank top
- attach deco bottle bottom while main tank is off bungee (see below)
- attach deco bottle top
- put the main tank on bungee
- put the bottle on bungee

Donning-bottle

• kr2y5
• Jul 31, 2016

That'd mean the stages/deco would be bungeed over the top of the primaries.

Yes, that's what I'm doing.

If you then partially detached the primaries and swung them forwards, it'd create some twisting pressures on the stage/deco bungees. I'd predict it might push the bungee off the handles?

Possibly. The left deco bottle sometimes came off the bungee, I'm making 2-3 turns around the knob now. The right bottle is around the knob, but the knob is inwards, so it's secure. I'm replacing the valves with a pair of proper mirrored modular valves so that I can bungee around the post on both bottles. With the deco bottles it's a non-issue, because I'm working with a much longer and more stretchy bungee, and I have no difficulty looping it around or taking a couple turns. For some reason, I'm having a hard time doing the same with the main tank bungee.

Also, what is the issue with not getting loop bungess to work on a Contour? I've put loop bungees on every rig I own, or have trialled, thus far. I've never seen an issue, as long as you have some grommits or a D-ring at the back. It should be set-up so that the bungees runs hortizontal back to chest... but that's normally a factor of rig adjustment.

Not sure, that was a comment by Richard on this recent thread I started. Perhaps the bulk of the drysuit with the heavy undergarments and weight of the tanks makes it an issue. I should probably call Edd, but then it doesn't really matter. At the end of the day, it has to work for me. I suspect everything can be made to work with a better bungee, I just need to find one or otherwise tweak my rig to make it work. I'll keep poking around and trying different bungees recommended by others, and tweaking this and that.

All I can say so far is that, I've tried to extend the bungee that came with Contour to the max possible length by putting knots at the very ends of it (which added something like, 4 inches length compared to the length I normally use), and I spent a good 15 minutes in the water trying to wrap bungees around the posts (for what little I do have them on the damned HOG valves), with no luck.

Of course, one could argue it's a skill issue that shouldn't be remedied by tweaking equipment, and if there are special tricks to it, I'd love to learn them. Ultimately, I need to be able to operate the valves while bungeed and get the tanks off the bungee and back on in the water without difficulty.

I did ask a couple of divers using the same rig how they do it, and it seems everyone I talked to is just looping around the knob. Same for divers in all the videos I've seen people diving Contour (including the promotional ones).

On the photo (above) it's a little low... should be more snug under the armpits.

Bothers me too, but if bungees are much shorter, I can't work with them. Here's how my tanks are aligned right now (I know, there are still some danglies to eliminate, the safety cords are too long and the swivel on the O2 regulator is sticking out). The goal was to align tanks with my legs, rather than torso, to keep the tank bottoms from bumping against stuff.

Thoughts?

Profile

• kr2y5
• Jul 31, 2016

Profile2

• kr2y5
• Jul 31, 2016

Profile-nobottle

• kr2y5
• Jul 31, 2016

 

[DevonDiver]

I've tried to extend the bungee that came with Contour...

This could well be a problem. What bungee comes with the Contour? Most cold-water rigs, from my observations, come with a thicker bungee. Loop bungee works best with a 6mm bungee. It's 'doubled' so there's no issues with having enough strength to hold the tank in position. The advantage of a loop bungee is that you get a lot of slack to reach the post... as it slides through the harness attachment.

With regards to deco/stages.... did you see the method that Steve Martin shows in his videos. It's similar to what Rob Neto described in his blog some years ago... Sidemount Stage Rigging

Use a basic worm-screw band on the stage/deco. Position it ~2" above where your bands on the primaries sit. The bolt snap is connected with 6" of 6mm bungee (not cord). At the top, make an bungee choker that holds the bolt-snap. This method keeps the stage/deco very trim and snug to the body. Take a little practice to don/doff the cylinder, but it's not hard. As with many things, you just need to get the technique right. That's where many divers fall down....

 

[kr2y5]

This could well be a problem. What bungee comes with the Contour? Most cold-water rigs, from my observations, come with a thicker bungee. Loop bungee works best with a 6mm bungee. It's 'doubled' so there's no issues with having enough strength to hold the tank in position. The advantage of a loop bungee is that you get a lot of slack to reach the post... as it slides through the harness attachment.

Contour comes with a pair of loop bungees that are very strong (densely packed rubber inside), they have about 80% maximum stretch, and at least visually appear to be the same 5/16 inch (8mm) bungee that Edd is selling on the Cave Adventurers website. I'm not sure who manufactues it, we seem to have something that looks and feels identical locally at a marginally better price.

With regards to deco/stages.... did you see the method that Steve Martin shows in his videos. It's similar to what Rob Neto described in his blog some years ago... Sidemount Stage Rigging

Use a basic worm-screw band on the stage/deco. Position it ~2" above where your bands on the primaries sit. The bolt snap is connected with 6" of 6mm bungee (not cord). At the top, make an bungee choker that holds the bolt-snap. This method keeps the stage/deco very trim and snug to the body. Take a little practice to don/doff the cylinder, but it's not hard. As with many things, you just need to get the technique right. That's where many divers fall down... .

Hmmm, I've watched Steve's video, and I thought I followed his directions fairly closely in terms of placement and length. I'll try to tweak the position a bit more, and see if it helps. I've already tried using a very tight choker, but that makes it harder to loop the finger through (as he recommends) and to manipulate the boltsnaps, and smaller boltsnaps didn't work for me.

I'm not sure how much it matters, but one MAJOR difference I do see is that, his tanks in general are positioned much more forward. I'm not sure if that's a cold vs. warm water thing, or whether they're supposed to be this way in either case. His valves are basically right in his armpits, and the bottoms of his tanks are right under his butt cheeks. In my case, all tanks are positioned much further in the back: my tank valves start at the level of the middle of my torso, and the bottoms of my tanks are just above my knees.

 

[DevonDiver]

Contour comes with a pair of loop bungees that are very strong (densely packed rubber inside), they have about 80% maximum stretch, and at least visually appear to be the same 5/16 inch (8mm) bungee that Edd is selling on the Cave Adventurers website. I'm not sure who manufactues it, we seem to have something that looks and feels identical locally at a marginally better price.

If possible, have a look/feel at the bungee that comes with XDeep rigs. This is optimal, from what I've tried. I'm always experimenting with different bungee types... the XDeep bungee has enough stretch, but is strong enough in loop bungees to support most cylinders easily.

Bungee tends to get sold by thickness... but I've never seen a categorization of it's stretch. It'd be useful if they did that.... LOL

I've already tried using a very tight choker, but that makes it harder to loop the finger through (as he recommends) and to manipulate the boltsnaps, and smaller boltsnaps didn't work for me.

What was the issue? Thick gloves?

Another issue with stage/deco streamlining is often the location of shoulder D-rings. It's hard to see on your pics where yours are located. They should be up (just immediately below) the collar bones.

If using a loop bungee... there's no connection or interference with the shoulder D-rings. These rings are then only for attaching stage/deco (and long-hose, on the right). Having the D-rings higher creates more length in the attachment, which brings the cylinders more snug into the body.

....his tanks in general are positioned much more forward. I'm not sure if that's a cold vs. warm water thing, or whether they're supposed to be this way in either case. His valves are basically right in his armpits, and the bottoms of his tanks are right under his butt cheeks. In my case, all tanks are positioned much further in the back: my tank valves start at the level of the middle of my torso, and the bottoms of my tanks are just above my knees.

That's because of where your loop bungees originate from at the back. As per your illustrated picture, your bungees start from quite low on your back. The bungees should be 'horizontal' from the back to the front... just under your armpits. Yours are lower. So your cylinders sit lower...

Using a sliding loop at the front makes things easier.... you just need to resolve your bungee attachment point at the rear.

 

[kr2y5]

Thanks, I will take a look and see if it can be moved. Sadly, this rig doesn't seem to be designed with much adjustability in mind Yup, the choker issue was thick gloves. I guess it's possible to work with a smaller boltsnap, just a little frustrating. I guess I could also try to use lower-profile D-rings and move the D-rings higher to shave an inch or two. It's also going to be easier with AL80s since they are thicker, so the "streamlined" effect is a bit easier to achieve than with AL40s