Open Water Technical Wreck Z-Sidemount Diving: Initial Impressions. . .

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Permalink Reply by Unified Team Diving on December 5, 2011 at 2:37pm

Kev

Thanks for the Update. I really appreciate your point of view. To help you a little with the disadvantages, I have found that if you rig the stages and tanks on the boat and clip the tanks up to the chest D-Ring - like normal backmounted stage bottles would be, and then only once in the water and descending do, I move the cylinders off the top d-ring and allow the bungee to pull them back into Side-mount position. This has worked great for me to relieve the hassel of attaching tanks while in the water, especially in rough seas.

AG 

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Permalink Reply by kevrumbo on December 6, 2011 at 1:42am

Yeah AG, I'm doing that now on the boat when gearing/kitting up. . .

Another note/comment when doing two bottle deco on technical Z-sidemount:

I'm clipping the two AL30 deco bottles, one on each side for better balance --and using the PADI DSAT mnemonic to keep track of them:  "Right side Rich" for Oxygen bottle, and "Left side Lean" for Eanx50

:-D

Unified Team Diving said:

Kev

Thanks for the Update. I really appreciate your point of view. To help you a little with the disadvantages, I have found that if you rig the stages and tanks on the boat and clip the tanks up to the chest D-Ring - like normal backmounted stage bottles would be, and then only once in the water and descending do, I move the cylinders off the top d-ring and allow the bungee to pull them back into Side-mount position. This has worked great for me to relieve the hassel of attaching tanks while in the water, especially in rough seas.

AG 

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Permalink Reply by kevrumbo on December 6, 2011 at 4:53am

Very easy & intuitive to unclip/dismount either one or both bottom mix standard AL80 tanks on the Z-system, and push them forward in the prone position when going through a narrow restriction (again do not ever use the heavier compact AL80's --they will flip/sommersault you over if you try the dismount technique!!).

I usually clip both bottom bolt-snaps of the tanks together and hold them forward in my right hand with my primary light in my left;  if needed I can hold both clipped bolt-snaps of the tanks and primary light in one hand while pulling & gliding along the wreck's passageway with the other hand.

For gas consumption monitoring, I typically start on descent with the Right Tank On/Left Tank Off for a delta of 40bar down on the Right Tank (160bar total remaining Right Tank) over an approx 4 to 7min time period depending on depth & workload.  Switch to Left Tank On/Right Tank off and delta down 70bar on the Left Tank (130bar total remaining Left Tank) over a 5 to 8min period again depending on working depth & workload;  switch back to Right Tank On/Left Tank Off and delta 70bar (90bar total remaining now in Right Tank) for another 5-8min period;  and finally conclude bottom time switching back to Left Tank On/Right Tank Off & delta 70bar (60bar total remaining now in Left Tank) as I start deep stops on my deco profile.  On deeper/longer bottom depths & times, I may switch back to the Right Tank one last time. . .

 

Using the following technical profile:

20/20 trimix with Eanx50 and Oxygen for deco;
Sidemount 11L tanks with 4.2L deco bottles.

The deep wrecks of the Fourth Fleet Anchorage (San Francisco Maru; Aikoku Maru; Nagano Maru; Shotan Maru; Nippo Maru; Hoki Maru etc), all fall in the Depth/BT ranges below. I just pick the average depth and the corresponding time on pre-dive planning and/or real time, on-the-fly during the dive as needed:

Depth: BT:
45m 35min
48m 30min
51m 25min
54m 20min
57m 15min

. . . And then the following same deco profile for any one chosen Depth/BT combination from above:

42-39m short deep stops 5 to 10sec
36m 30sec
33m 1min
30m 1min
27m 2min
24m 3min
21m 4min Eanx50 switch
18m 3min
15m 3min
12m 3min
9m 2:2min Eanx50:backgas break
6m 10min Oxygen switch
-->ascend 1m/min for 6min time to surface on O2

(based on Buhlmann GF 30/85, and Ratio Deco 1:1)
SCR: 10 to 12L/min; deco SCR: 12 to 15L/min;

Water temp 29deg C.

 

 

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Permalink Reply by kevrumbo on December 13, 2011 at 3:11am

Found that tucking the excess long hose length under the waist belt in front secures it better than routing under knife sheath and stuffing the excess behind the delta wing. . .

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Permalink Reply by Unified Team Diving on December 13, 2011 at 10:10am

I would agree, especially if you have a shorter torso and excessive length of long hose. Just stuff the excessive long hose it in your waist strap and slide it backwards as far as it will go.   Just make sure that the waist strap is tight enough to keep it tucked. We do this a lot in recreational instruction when the student does not own a light.

Andrew

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