I recently completed my solo certification using side mount as my redundant gas (over the initial objection of my not side mount friendly instructor, but I convinced her to treat my second tank as a big pony and kept gas off on right tank except for oog exercises). My rig is an apeks wsx25 using loop bungees, with lower attachment to the sliding D rings on waist for al tanks, or rear fixed d rings for steelies.
With solo, however, I found I needed more attachment points than I had easily available. 2x cutting tools, lights, dsmb plus safety sausage, extra mask, visual signaling device, 2x audible signaling devices... Mostly clipped to my shoulder d rings (except dsmb in butt pouch, and extra mask strapped to a thigh pocket, and I put one of my knives on should strap tucked under d ring).
With all of that extra gear, my shoulder d rings were pretty overloaded (and I also use my right shoulder d ring to secure my inflator, plus a clip for my long hose..)
Plus, I always have a big camera rig which I usually clip to the shoulder D rings also when I need hands free.
Anyway, I quickly realized the my much loved minimalist wsx might be too minimalist for solo diving. I just could not come up with any good solution for more attachment points for all my solo diving Christmas tree ornaments. Maybe I could add D rings above the should D ring but that would ride pretty high on my shoulder? Nothing possible on waist belt due to sliding D rings.
Curious what others do for adding attachment points.
Am considering Hollis rig due to the built in attachment rings on side, but I am really comfortable with my wsx and hate to change up.
Any other thoughts or ideas?
echoing some of the above
Big butt pouch is likely the answer. I can't stand thigh pockets in sidemount since they are very annoying to get into and they make the tanks feel funny when they're full. I don't even have them on the drysuit I use primarily for sidemount. The wetsuits from Deep6 had them canted forward for easier access but does make them hang forward which is annoying. I've been sidemount diving since 2009, long before it was "cool" and when the Razor, Armadillo, and original Nomad were the only commercial options out there, so I've tried most of this in the past and this is where I've settled.
2x cutting tools: z-knife strapped to each of your computers and/or chest strap. I use Benchmade 7's but the trilobites work the same. Thread the bungees for your computer/compass through the strap and you're good to go. Since you're probably diving in the lakes up there you NEED and no this is not negotiable, you NEED trauma shears. Those can either go in a pocket or on your waist strap but with all the fishing gear in there you do need shears.
Lights: unless you're doing penetration you only need 1x spare which can easily be clipped into the butt pouch with the other on a goodman handle on your hand. I am partial to the Oxycheq Raider that is best to get from Cave Adventurers. If you are doing penetration then get a helmet and put them on your head or you can tie one to your mask strap. If you google pictures of @Edd Sorenson
you will see a mask light on his mask and depending on the age of the image a Paralenz attached in similar fashion on the other side.
DSMB: If you intend to use it, just clip it to your butt d-rings, if you don't intend to use it then in the butt pouch it goes.
Spare Mask: butt pouch
Signaling devices: butt pouch.
Wet notes: you didn't mention these, but you should probably have them and they should be in the butt pouch.
NOTHING should be clipped to your shoulder d-rings unless you intend to use it frequently during the dive. Those are meant for things you need readily accessible and none of the things you have mentioned belong up there *with the one possible exception of backup lights if rigged DIR style but those usually get in the way of the bottles if they are rigged properly.
I do not recommend pocket shorts, certainly not for cold water diving I don't know how big the Apeks butt pouch is, but do not be afraid to stuff them, everything should be clipped to a bungee loop so you can pull it out and stuff it back without dropping anything.