BP/W vs Sidemount

[Bubble_blower87]

Can a bp/w do both or is it mostly for back mounted doubles?

 

[cool_hardware52]

Can a bp/w do both or is it mostly for back mounted doubles?

BP&W was originally developed for back mounted doubles. It's become quite common for back mounted singles.

Side mount is a different animal. While no doubt all sorts of adaptation is possible, I'd suggest you would be handicapping yourself to try and use a BP&W for sidemount vs a dedicated SM rig.

Tobin

 

[Bubble_blower87]

I was thinking the same thing. But when looking at some like sms hollis it looked similar to a bp/w. I've been looking at the dive rite nomad.

---------- Post added November 30th, 2015 at 06:24 PM ----------

Also I see guys with doubles and side mount. I'm assuming they customized it though.

 

[JohnnyC]

Also I see guys with doubles and side mount. I'm assuming they customized it though.

Typically that's guys who are using sidemount techniques to rig stage/deco/bailout bottles. In my case, I use a buttplate and bungees to sidemount them so they are streamlined.

 

[tbone1004]

so your question brings up a couple things.
The doubles with sidemount is usually a dedicated backmount system where the deco and/or stage bottles have bungees around the necks for better trim than the traditional routing. My backmount setup has the ability to accept sidemount bungees to hold tanks up for this reason.

Some sidemount rigs can be used with doubles. The Nomad is much better at it than the SMS series from Hollis because the Transpac was designed originally for hauling doubles. The wing was based on an original backmount wing and the buttplate was added. It works OK for sidemount and while I use one as my primary rig it was custom to begin with and has had more customization done.

Now, here's the reason sidemount rigs aren't ideal for use with backmount. Trim. Sidemount has a significant amount of weight placed around the hips which causes the divers to trend feet down. This is countered with any combination of shoulder weights, neutrally buoyant fins, and extra air in the feet of drysuits. Twinsets on the other hand will almost always push you head down due to the added weight of the manifold, bands, etc. and this is countered with tail weights, negatively buoyant fins, and some drysuit users will use gaiters if their suit isn't fit properly. The wings are opposite for the other style of diving.

Hard backplates can and have been used in sidemount, but in a cave it is dangerous because they can initiate a ratcheting effect in true sidemount passages, which is bad.

The trim issue is reason enough to have dedicated systems. Single tank sidemount is quite easily done when travelling and is becoming more common, so there is no need to strap a single to your back, but it isn't a bad feature to have if you end up with a particularly annoying dive operator, but you should really try to commit to either sidemount or doubles in your training


Where are you in NC? If you want to look at some rigs, let me know. I'm up there somewhat regularly and have a handful of different rigs and access to many more

 

[decompression]

Tbone raises some very good points. I have about 100+ dives on a backplate SM, essentially because one of the areas I dive is cold water (30-40 F) so it can be challenging to place lead. As I said, I have a bp SM system, meaning the wing was designed to work with a backplate but there are only a few like this. There are draw backs, mobility being one and for that reason tight restrictions in overheads are avoided. However, in a drysuit, serious undergarment and 40 lbs of lead, your mobility is restricted anyway. A few of the SM rig address the lift issue by the use bungees allowing you to control where the lift is in regards to your body. Some are better than others. So, as mentioned, if you start with a do it all rig you may soon out grow its ability in one specialty or the other.


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[DevonDiver]

BP&W make pretty lousy sidemount rigs. The biggest problem is that the wing bladder will taco (rise upwards/inwards) unless restrained. There are a number of conversion systems on the market (see list of available sidemount adapters here: A List of Modern Sidemount Diving Systems).

However, even with a conversion, they won't have the same distribution of buoyancy across the torso as a dedicated sidemount system, won't have the right connections and layout, etc etc...

I made my own conversion many years ago; using the OMS Profile Adapter with a Custom Divers TDB backplate and wing. The metal backplate was atrocious to dive (and an entrapment hazard inside wrecks); so I also swapped it out for a soft (Oxycheq) backplate. Then I found the buoyancy/lift wasn't where I needed it - so I have to use bungee cord to shape and tailor the wing; cinching in around the top to focus lift over the lower half (across the lower back and the hips). It was a major project and required lots of sidemount diving experience and numerous modifications to achieve a workable result. Even then, it doesn't perform anywhere nearly as nice as any of the dedicated sidemount rigs I own. See details of the conversion project here: Some Options for DIY Sidemount Rigs

Back to the original question: Yes, you can convert a BP&W to use as a sidemount system. However, the results will be far less desireable than a dedicated sidemount rig. It's kinda like asking if you can convert a city car for use off-road. Yeah, you *could* but it'd be a timely and costly project and it'd never work so well as a Hummer, Land Rover etc...

There are so many sidemount rigs on the market nowadays, at all ranges of budget: there's just no need to BP&W for doing a job it is not designed to do, or suitable for. A List of Modern Sidemount Diving Systems

Rigging deco/stage cylinders onto a BP&W is not the same as sidemount diving. I've seen some (very ill-informed) supposed sidemount divers/instructors trying to pass this off as sidemount diving.... but it's laughable. Sidemount diving is defined by having the cylinders mounted in trim with the torso. Proper configuration puts the valves under the armpits, with the cylinder retained along the side of the body to the hips. It should not deviate above, or below, the same angle as the torso; as if you drew a line from the shoulder to the hips/knees. This invariably requires a bungee system to support the cylinder at the neck, and a bolt-snap arrangement on the mid-lower cylinder. The sidemount bladder itself tends to focus lift at the lower back/hip area; promoting proper horizontal trim in the diver.

For more insight into what is... and isn't.... sidemount do take a look at my comprehensive notes here: Sidemount Diving | Course Notes | Advanced Scuba

 

[decompression]

Andy makes some great points.

This is the only rig I've dove that works with a backplate, has plenty of lift (adjustable) placed in the right spot and routes the bungee through the wing to keep it streamlined. A tough, streamlined wing for cold water diving.

Although, I think the OP is just asking about the SM/BM rigs out there.


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[Bubble_blower87]

so your question brings up a couple things.
The doubles with sidemount is usually a dedicated backmount system where the deco and/or stage bottles have bungees around the necks for better trim than the traditional routing. My backmount setup has the ability to accept sidemount bungees to hold tanks up for this reason.

Some sidemount rigs can be used with doubles. The Nomad is much better at it than the SMS series from Hollis because the Transpac was designed originally for hauling doubles. The wing was based on an original backmount wing and the buttplate was added. It works OK for sidemount and while I use one as my primary rig it was custom to begin with and has had more customization done.

Now, here's the reason sidemount rigs aren't ideal for use with backmount. Trim. Sidemount has a significant amount of weight placed around the hips which causes the divers to trend feet down. This is countered with any combination of shoulder weights, neutrally buoyant fins, and extra air in the feet of drysuits. Twinsets on the other hand will almost always push you head down due to the added weight of the manifold, bands, etc. and this is countered with tail weights, negatively buoyant fins, and some drysuit users will use gaiters if their suit isn't fit properly. The wings are opposite for the other style of diving.

Hard backplates can and have been used in sidemount, but in a cave it is dangerous because they can initiate a ratcheting effect in true sidemount passages, which is bad.

The trim issue is reason enough to have dedicated systems. Single tank sidemount is quite easily done when travelling and is becoming more common, so there is no need to strap a single to your back, but it isn't a bad feature to have if you end up with a particularly annoying dive operator, but you should really try to commit to either sidemount or doubles in your training


Where are you in NC? If you want to look at some rigs, let me know. I'm up there somewhat regularly and have a handful of different rigs and access to many more

Hey man I am north of charlotte and would love to have someone let me see the gear. My shop has some but I don't always have the ability to be at the shop. They are just getting into doing sidemount stuff too, with their first rigs coming in only 2 weeks or so ago.

 

[bamafan]

There is a guy in Germany who has a large following named Toddy. His sidemount system is based around a wing sandwiched between two backplates. I don't recommend it for true sidemount diving as like Tbone said it will get you stuck. His desciples will say otherwise. It is definitely being done by a large group of people. A Google search will also turn up some of his videos.

sidemount explorer: Das System