Revo "dilout" modification thoughts

[Wibble]

Thoughts about modifying a Revo for use with "dilout"...

Flying off to a warm location where the pretty fish play in the warm water and excellent visibility; diving to air diluent depths only. Aside from the Pelicase being too heavy(!), the Revo's a great rebreather. However, renting 3 litre cylinders gets expensive for a week. Actually it's renting two 3 litre cylinders (or 2 litre) and the bailout.

So for a thought experiment wondering about taking a leaf from the chestmount/sidemount book and modifying the Revo to remove the diluent cylinder and plumb it directly into the bailout using a QC6.

On first appearances this seems to be possible; remove the first stage, replace the LP hose into the manifold with one terminated into a QC6 which would be connected to the bailout first stage.

In action it should be an ali7 or ali80 with air diluent/bailout which would be topped off as it's used. Still have the oxygen 3 litre cylinder, but saves on the diluent.


Ignore the engineering detail for now: what utter stupidity is this?!? It's more or less the same as a Triton, Choptima, Sidewinder, SF2...


Again: just a thought!

 

[Marie13]

Not just sidemount… my Kiss Spirit has dilout, too. Will definitely be easier for your ocean vacation diving

 

[kierentec]

An issue I’ve seen overlooked a lot lately with the chest mount and sidemount CCR crowd is by carrying only one bottom bailout cylinder and using it for dil, you are now essentially just carrying one big diluent cylinder and no bailout. If using “dilout”, you need to be carrying two separate bottom bailout cylinders. Otherwise you’re one o-ring or hose failure away from a really tricky situation with very few options.

 

[lostsheep]

An issue I’ve seen overlooked a lot lately with the chest mount and sidemount CCR crowd is by carrying only one bottom bailout cylinder and using it for dil, you are now essentially just carrying one big diluent cylinder and no bailout. If using “dilout”, you need to be carrying two separate bottom bailout cylinders. Otherwise you’re one o-ring or hose failure away from a really tricky situation with very few options.

Yep, matching sidemount bottles or doubles for my bailuent on the chop…period.

 

[broncobowsher]

Doesn't the Mares Horizon do that? It pretty much started life as a rEvo anyway.

 

[Wibble]

Doesn't the Mares Horizon do that? It pretty much started life as a rEvo anyway.

It's a SCR, so should be bubbling behind the head.

But yes; should be very similar.

 

[Heat Miser]

An issue I’ve seen overlooked a lot lately with the chest mount and sidemount CCR crowd is by carrying only one bottom bailout cylinder and using it for dil, you are now essentially just carrying one big diluent cylinder and no bailout. If using “dilout”, you need to be carrying two separate bottom bailout cylinders. Otherwise you’re one o-ring or hose failure away from a really tricky situation with very few options.

Thanks I dive the Chop single tank back-mount but I'm just getting started 8 hours and it seems easier on a boat where there is no deco and I don't dive solo. It would be different in a cave or with deco obligation. Am I missing something here isn;t the risk the same as single tank diving?

 

[tbone1004]

An issue I’ve seen overlooked a lot lately with the chest mount and sidemount CCR crowd is by carrying only one bottom bailout cylinder and using it for dil, you are now essentially just carrying one big diluent cylinder and no bailout. If using “dilout”, you need to be carrying two separate bottom bailout cylinders. Otherwise you’re one o-ring or hose failure away from a really tricky situation with very few options.

Fact. I tend to believe that the rebreather needs to be "in addition to" the base open circuit gear that you would normally take on a dive and not replace any parts of it. There are obviously times when a single bottle is perfectly appropriate for a CCR dive but that is usually limited to filmography type dives where you would be able to conduct the dive on a single tank but are using the CCR for bubble mitigation. Note I did say the base configuration which includes the deco bottles, it certainly can replace bottom stages for deep/long dives but it should never replace the base open circuit requirements or deco bottles.

With regards to the Revo in particular, if it is set up for offboard gas addition it is set up for offboard gas addition. If it is not, then make it. It has been years sine I have dove a Revo and none of my buddies use them so I'll plead ignorant to the "stock" setup and certainly to @Wibble 's specific configuration but I am familiar with the triple MAV and it's as simple as having the bottles plug in with some sort of standard configuration. O2 I tend to prefer BC inflators and if you are not using a BOV then you can certainly use those for the dil as well. No need for QC6 IMO unless you are using a BOV, standardizing with a team, or already have them for whatever reason.
Word of caution with the BC inflators though, they do let water in so try not to connect/disconnect them underwater when diving in the salty stuff, especially if you have a CMF...

 

[Wibble]

With regards to the Revo in particular, if it is set up for offboard gas addition it is set up for offboard gas addition. If it is not, then make it. It has been years sine I have dove a Revo and none of my buddies use them so I'll plead ignorant to the "stock" setup and certainly to @Wibble 's specific configuration but I am familiar with the triple MAV and it's as simple as having the bottles plug in with some sort of standard configuration. O2 I tend to prefer BC inflators and if you are not using a BOV then you can certainly use those for the dil as well. No need for QC6 IMO unless you are using a BOV, standardizing with a team, or already have them for whatever reason.
Word of caution with the BC inflators though, they do let water in so try not to connect/disconnect them underwater when diving in the salty stuff, especially if you have a CMF...

(The "thought" process arose because I was using 2 litre dil + oxygen cylinders on a 150 min dive which was rather undulating between 20m/65ft and 40m/130ft whilst using a wetsuit (drysuit socks sprung a leak on the first dive!), so all buoyancy was off the 2 litre diluent. Had to connect the bailout to the BCD to save the diluent for the loop.)

 

[mr_v]

How much do you plan to save and is it worth it?

I started thinking "dilout" after trying Fathom. However, my thoughts were not related to saving $ at all.