Hollis SMS 100

[DevonDiver]

.. you can just not use the butt plate and add some d-rings, that part is not a big deal.

It's a big deal because the buttplate isnt removable. So you can add D-rings... but probably not where you need them to be.

... AL tanks on your waist, it's like you suddenly have a whole extra 6" of wing at the bottom... it meant I was suddenly VERY butt-light and it was a real problem getting enough weight low enough to correct for it.

Systems designed for aluminium cylinders also keep most of the buoyancy low on the torso, but balance that by having options to keep the weighting low also.

Many sidemount divers don't appreciate the inherent differences in sidemount diving steel and aluminium cylinders - even to the point that there's really two distinct design heritages in sidemount evolution.

The Two Schools of Sidemount Diving Heritage

Also, with the inflator and dump reversed, the gas had to move all the way from by butt to my shoulder to dump, and that meant going WAY out of trim to dump

Yeah.... I've yet to figure why US sidemount manufacturers remain pre-occupied with top-mounted LPIs.

What's horrific about the SMS100 is that it doesn't give you a choice to swap the LPI low. If you do... there's no lower OPV/dump available.

.. about hybrid rigs, but I think the Toddy-style rigs are a good try, and seem to me to be a compromise only on the SM side, and even then not necessarily a BAD SM rig. I haven't tried them....

I used, what is basically, a toddy rig for years before I could get a dedicated sidemount rig (back when it was just the Armadillo and DiveRite available... and they weren't available in Asia).

Workable? Yes.
Providing the full spectrum of sidemount benefits and comforts? Hell no...

People get hybrids to save money on buying two systems. They inevitably already have a backmount rig.

For the cost of replacing an existing backmount-only rig with a hybrid BCD... or buying all the bits you need to build a Toddy... nowadays you can just buy an economical dedicated sidemount rig.

Just look at the Deco Sidemount.... it's less than $250. More than sufficient for recreational or tech-lite on your tropical vacation. I've dove it with 4xAL80. It's also tiny bulk and incredibly lightweight.

 

[Bennno]

... there's no lower OPV/dump available.

And what do need a lower dump for? Have you ever used a dry suit Andy? Where is the lower dump on the suit? A lower dump just adds an unnecessary failure point.

Other than that, I agree that the SMS100/75 is one of the worst rigs ever for AL80s and so is the Toddy System. With steel tanks (which are much better for dry suit/cold water diving) the Hollis rigs are OK, not great but OK.

 

[Aotus]

It's a big deal because the buttplate isnt removable. So you can add D-rings... but probably not where you need them to be.

Again, I generally agree with your last post as far as my experience allows. But, I have to again disagree about this point about d-rings. This is not the issue, and it IS easy to put them where you need them. The "butt plate" on these rigs is also more of a "lumbar plate" so it isn't as low as those on DiveRite and similar rigs. I think your arguments in your earlier post wold apply more to DR BCs.

 

[Aotus]

And what do need a lower dump for? Have you ever used a dry suit Andy? Where is the lower dump on the suit? A lower dump just adds an unnecessary failure point.

I agree that having multiple dumps theoretically adds unnecessary failure points. But, with the way the sms rigs are built, a low dump would require less movement out of trim to dump. Maybe less of a problem with the 100 because of the shape of the wing. If I still had a SMS75, I would certainly add a low dump valve for diving with aluminum tanks.


As for the toddy system. I haven't tried it so I can't argue that point. I hope to get the chance so I can understand the issues.

 

[Bennno]

But, with the way the sms rigs are built, a low dump would require less movement out of trim to dump.

No, it does not require more movement, why would it? When diving dry suit the opposite is true! Ass up for dumping the wing and than shoulders up for dumping the suit.
Even when you're in perfect trim you can use the shoulder dump. This whole 'lower dump issue' has been brought up by people (wet suit divers) who wanna sell the stealth... and people are buying the story. The stealth needs thh lower dump because it's super bulky when inflated. If they had a better wing design they wouldn't need it. They're fixing crappy wing design by putting the dump where it is now.
Do a bunch of accents (more than 30') in your stealth and a dry suit and you'll see how annoying it is and how much more you need to move to dump the suit and the wing.

If I still had a SMS75, I would certainly add a low dump valve for diving with aluminum tanks.

The 75 is a rig for steels. Makes no sense to use it with ALs.

 

[DevonDiver]

And what do need a lower dump for?

Oh, I dunno mate. Maybe you should ask EVERY wing designer, sidemount and backmount, instead?

Every sidemount BCD comes with a lower OPV. Let's remember that this is only a issue on the SMS100 if you want to swap the LPI position.

I just think that Hollis hadn't considered that many divers would want a lower LPI when they designed it. It ships with the OPV lower. Moving it is a user modification.

You have to remember that the SMS100 has been around for a while. The only inspiration the design team would have had back then was the Armadillo and DiveRite. Sidemount design has come a long way since then.

You'll also notice that the Hollis SMS50-S was designed for a swappable LPI. That model has an extra low LPI for exactly the reason were discussing.... So Hollis 'got it', even if you're still struggling with the idea Benno

Have you ever used a dry suit Andy? Where is the lower dump on the suit?

Just once, or a few thousand times.

You raise your arm to dump in a drysuit. It doesn't force you out of proper trim.

Aotus already explained the problem back on page 1.

With steel tanks (which are much better for dry suit/cold water diving) the Hollis rigs are OK, not great but OK.

True. In common with many US sidemount manufacturers it follows the Florida cave style for steel cylinders. There wasn't a lot of insight into aluminium tank diving practices.

I've not had chance to get my hands on one yet in the Philippines, but the new Hollis Katana seems much more adept as for both steel and aluminium cylinder divers.

 

[DevonDiver]

BTW.. for the OP @nbkoc ... Here's a list and specifications for the main hybrid sidemount BCDs on the market..

Top 5 Convertible Hybrid Sidemount Systems

 

[Bennno]

Oh, I dunno mate. Maybe you should ask EVERY wing designer instead?

Balony and you know it. Look at all the rigs on the market. Most 'designers' have no bloody clue what they're doing, 3/4 of the rigs on the market are just crappy Razor rip-offs. As for the other experts: Do you think Hollis even has a SM diving designer on staff? What about SP or the guys who make the Finnsub or the crappy TecLine wings?
You are always deflecting direct questions.
You absolutley do not need a lower dump, at least not one if you're a comptent dry suit diver.

Just once, or a few thousand times.

You raise your arm to dump in a drysuit. It doesn't force you out of trim.

You aren't forced out of trim when using a shoulder dump... lower dumps are for warm water/wet suit divers only and even they don't need it if they have proper trim.
If you really have used a DS thousands of times you'd know that in order for the gas to leave the suit through the dump it has to travel over your shoulder, as most peoples armes are attached to their shoulders. The same trim that allows you to dump the suit also allows you to dump the wing.

 

[DevonDiver]

Not sure if you don't understand proper trim, or if you just lack commonsense?

Name ONE SINGLE sidemount or backmount wing that doesn't have a lower OPV as standard?

Now...name all the rigs that have top mounted LPI? (clue: out of ~52 rigs on the market, and rising, you'd count this on one hand..)

A List of Modern Sidemount Diving Systems

But, as you say... "all" the sidemount manufacturers know nothing, and you're the sole true authority on the matter.....

I come on Scubaboard to help educate, not to get trolled. I've responded thus far purely for the benefit of the novice sidemount divers who might browse the thread. Don't feed the trolls folks...

 

[Bennno]

Not sure if you don't understand proper trim, or if you just lack commonsense?

LMAO, yes Andy. I don't understand proper trim.

Name ONE SINGLE sidemount or backmount wing that doesn't have a lower OPV as standard?

Armadillo doesn't have one and it's actually designed by real SM divers. Razor has the dumps on the side and no lower dump and it's also designed by real SM divers. Cave divers. Coincidentally, those 2 rigs are at least within the top 5 best rigs on the market right now.

I come on Scubaboard to help educate, not to get trolled. I've responded thus far purely for the benefit of the novice sidemount divers who might browse the thread. Don't feed the trolls folks...

I'm not trolling. I disagree with your points. You just call it trolling because you never have an answer to direct questions or criticisim.
You can dump your wing without a lower dump while staying in trim, that's a FACT!

I didn't know you here to help, I thought you're here to plug your website in every thread.

Sorry for daring to doubt Mr super instructor.