Some Hollis SMS100 modifications...

[DevonDiver]

I put together a short article detailing some of the super-simple modifications to the Hollis SMS100 sidemount that I've developed with students over the last few years. I get students for training in many different sidemount rigs and we do equipment set-up/tweaking workshops for all... but the SMS100 is certainly one rig that really benefits from some fine tuning for warm-water diving...

Hollis SMS100 Sidemount Modifications

 

[rick00001967]

i read this on your web site. all seem like good ideas for sure. i was a bit confused on your description of the pros and cons of attaching the tank bungees to the harness by either a bolt snap vs a small bungee loop. i have tried both. in cold water i much prefer the bolt snap only because it makes it much easier to find with heavy gloves on etc. but it was your description of how to hook the bungees to the tank valves that i was unsure of. you stated when using the small loop to use your thumb to hook the bungee around the valve stem (when using opposing valves) but gave no description of what you do when you use bolt snaps. i hook my tank bungees the way you described no matter whether i use a small loop or bolt snap. so i am curious what method of hooking the bungee to the tank you would use if using a bolt snap. are you assuming that some people unclip the bolt snap and wrap the bungee around the tank neck and then reclip the bolt snap ?? i have seen some do that but not sure why they feel it is necessary.
you always offer tremendous info for all of us learning sm. thx for that !!

 

[DevonDiver]

I do route the bolt-snap around the tank valve when I am using that method - for me it's primarily a safeguard for technical wreck diving. I often have to partially remove cylinders to pass restrictions and when hooking the bungees only, I've had the tanks drop out and smash down onto floor. It's not reassuring when you are 5 decks from daylight in a cramped, silty engine room.. The loop bungee is a little more secure, but I've still not developed enough confidence in it for the particular penetration diving I do... looping the bungee around the tank neck is a cast-iron method.

In classes, I now teach both... and let the student select according to the pros and cons. I have both bungee methods on varying rigs.


Of course, you also need to unclip/wrap the neck, if you are using cylinders that have no stem and/or are not left/right-handed. That's a very common problem in many holiday diving locations. Hence, teach 2 methods - wth bolt-snaps being the 'universal' working approach, and loop bungee being (IMHO) the optimal approach, but dependent on the valves that are available.

 

[rick00001967]

seeing as hooking the tank valve stem helps rotate the tank into position......how then do you get the tanks to sit the way you want when simply wrapping the bungee around the neck ? or do you just adjust the position of the bolt snap on the lower tank band ? and then the bungee acts like a cradle on the tank neck rather than pulling / rotating it from the stem

 

[DevonDiver]

If there's no valve stem to hook around, then you need to anticipate that the (aluminum) cylinder will roll when you change the lower attachment. It's about a 90-degree roll.

I educate my divers on their options for that also. They have:

1. Start - Valve handles down / Finish - Valve handles horizontal
2. Start - Valve handles horizontal / Finish - Valve handles upwards.

Both options have pros and cons.

It'd be nice if ALL dive centers had stemmed valves... even better, left/right-handed valves... but most can't even manage DIN still....

I have a good selection of valves and tanks (sizes/materials) where I primarily teach. But I'm conscious that when students finish training, they probably have to cope with the realities of travelling/renting around SE Asia, where 'perfect' solutions and ideal support for sidemount is lacking.

(or... as Steve Martin says... "carry your own valves with you; and ask dive centers to fit them to your rental cylinders". I can imagine how that'd go down (..badly..) in the average tourist dive center here in Asia. LOL)

 

[rick00001967]

(or... as Steve Martin says... "carry your own valves with you; and ask dive centers to fit them to your rental cylinders".

this is what i did on my first sm trip. i was lucky enough that i have a good relationship with that particular dive shop.
thx again for all the great info !!

 

[Bennno]

Hi Andy,
I used to put weights on the backplate of my SMS as well but I didn't like the profile so I ripped out the foam of this cushion thing that comes with the SMS and put weights in.
It works great, give you a better profile in you don't even feel it since there is empty space between you back and the backplate anyways.
Have you tried that?

 

[DevonDiver]

These are modifications done for students who turn up for training with an SMS100. Normally, those rigs are brand new (not what I'd recommend for SE Asia diving, but not everyone seeks counsel..). I limit my modifications to the non-destructive type.

 

[Bennno]

I limit my modifications to the non-destructive type.

Those aren't fun though.

 

[Dive Right In Scuba 2]

Amazing write up! Thanks for posting this!