how to sidemount with lp72's

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Bowers

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Scuba Instructor
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I have recently been getting into sidemount. I took the class wearing a manta and lp85's clipped to a butt plate, with no problem getting things to trim out.
Then i put together my own sidemount rig that is fairly minimalistic. I dove with al40's clipped to d rings on my waist the other day and they worked great.
THEN i tried lp72s. as a steel tank i figured i would attach to a butt plate, but they got floaty in the back halfway through the dive. so a couple days ago i tried them clipped to the waist d rings (2 positions) like ali tanks and had decent success, but still had trouble with what seemed like floating when on the rear dring and sinking when on the forward d ring.
With such a lightweight steel tank, how do YOU sidemount them? I'd like to know where your boltsnap is positioned, how you attach the tank to your bc/harness, and any other details you have found to make them behave properly.

thanks in advance!
 
I am not truly a sidemount diver but I thinking more and more about giving it a go since I started carrying a pony bottle.

Here is a website that has some good advice on how to measure to get things set up. I pretty much followed the guidelines given and it has worked for me:

Ultimate Guide: How To Set Up Your Sidemount Harness (check the associated links towards the bottom of the page)http://scubatechphilippines.com/scuba_blog/how-to-set-up-sidemount-harness/

I basically made a copy of Dive Rite's Nomad bungee rings, minus the quicklink at the backplate....I took 6mm bungee and passed it through a 2" stainless steel ring and then passsed the ends through my one of the holes in my back plate and knotted them together with an overhand knot to keep the bungee from pulling through. I have stainless quicklink and connected to the ring with a bolt snap that gets connected to a d-ring that I put on my harness under the position of my standard shoulder d-ring. I made a choker to keep my upper bolt snap against the tank neck/valve by forming a small loop of 6mm bungee by tying the ends with double fisherman's knots and then stretching it over the valve and clipping the upper boltsnap into to the loop.

The guide in the website indicates to measure from your armpit to the lower clipoff point and then measure from the tank neck down that amount to place your lower attachment point.

With my setup, I found that I had my lower bolt snap on too long a leash which cause my bottle to not sit in proper trim. I shortened that up a lot and it made a tremendous difference.

My bottle is a steel 3L and since I am carrying it for safety/redundancy considerations for which I have yet had a need to use it, the only time I am breathing it down so far is when practicing deployin/restowing the 2nd stage on it ...so I have not experienced what it would feel like/how it would trim out when near empty.

I hope you can find some good info at the link above, it helped me as I researched how to get myself situated and as I get closer to making a move to full sidemount I will probably re-visit the info on the site.

-Z
 
yep Andy Davis Scuba Tech Philippines for all diving learning not talking
 
There are so many variables with sidemount gear and configuration, it’s probably not likely you are going to get a straight answer on this.

One answer is switch to a tank better suited for this. I own several sets of LP72. I have used them for Sm, but usually only when I am cavern diving and want to be solo, or are a 3rd diver.

I will not cave fill these anywhere close to what are in my typical LP85 or hp100s. If I really NEED sidemount, and redundancies, these are not the best tanks.

Now, if you really persist in using these. It is possible. I have added 2# weights to the cam straps, but there are plenty who will argue why that’s a bad idea.

Another option is to use either sliding D rings, or a belly bungee to pull the tails down when they get positive.
 
Another option is to use either sliding D rings, or a belly bungee to pull the tails down when they get positive.

Again I am not a sidemount diver...but it would seem that having bungee or other strapping crossing in front of the body would go against the grain of the prevailing thought of keeping the front as clear as possible and as it couldpresent an entanglement hazard....why not just add a D-ring to each side of the waist strap of the harness and workout the best position to locate them based on the buoyancy characteristics of the tank? One can add more than 1 d-ring per side if the buoyancy characteristics change significantly as the LP72 cylinders are breathed down.

-Z
 
thanks for the help guys. what i most recently tried was multiple d rings so i could change positions during the dive. it kindof worked but wasn't as "clean" as i would've liked. i just ordered some 401 o rings to try as sliding attachments, so that may work. i was tempted to try lead on the tank but am trying less cluttered options first.
 
If you're having to add weight to your waist, consider adding some of it to your LP72s. I do this with AL80s and it works well. 3 lbs near the rear (using a pocket) and I never have to worry about butt shift.
 
72s are highly variable based on year and manufacturer too. The Norris ones I have ride like Faber lp85s - at least in freshwater. 2lbs taken off your waist and threaded onto the cam band is the simplest solution if yours are genuinely floaty.

Any video or still pics of how they are ridding along with the neck bungie situation?
 
i dont have any pictures in that configuration. I'm using loop bungees over the valve knob and the knob sticks straight out to the sides. i put my lower bolt snap at about 45* below center like i did with aluminum 40 tanks (wich trimmed out great), and attached to drings on my waist.
with the aluminum tanks they felt stable against me and once adjusted they stayed put. with lp85s it was the same way. but with the 72s i would move them to the lower d ring once they felt floaty then feel like i needed to move them back up because they hung below my leg then floaty again and so forth...
 
i dont know if it helps but this is what the same rigging looked like with aluminum 40's
EA92AC99-DBDB-4CAB-B27D-A73053C49108.jpeg
1E79C20D-8F47-4F50-B77D-BB49FF7A9F9B.jpeg
 
https://www.shearwater.com/products/perdix-ai/

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