+ Reply to Thread
Results 1 to 3 of 3

Thread: One month with the Sub-Gravity Defedner

  1. #1
    RBW Member goodlifedivers is an unknown quantity at this point goodlifedivers's Avatar
    Join Date
    Jul 2014
    Location
    Oyster Bay
    Posts
    17
    None

    One month with the Sub-Gravity Defedner

    Our honest and long review of the Sub-Gravity Defender CCR...


    A Month with the Sub-Gravity Defender


    June 9th marks 30 days with my New-to-me Sub-Gravity Defender. These are my thoughts so far about the unit and making a direct comparison to my other unit the ISC Classic Megalodon.



    Admittedly, I donít have the berth of experience as most, on any unit, and take any of my gripes or compliments with a huge grain of sand. I should also disclose that my company is a dealer for Sub-Gravity and I am very happy to deal with them and to sell their equipment.
    A bit about my experience diving CCR to date. I have only used three units, a Meg, the Defender and during a quick pool session I played with a Hollis explorer. After being trained on the Meg I built up a little over 100 hours within a year diving in different conditions ranging from the North florida caves, Northeast atlantic and the chilly pacific and only to a depth of 170 feet. The majority of the hours I built up were wreck diving in the Northeast atlantic, with a sprinkle of shallow beach dives using the CCR as an O2 only rig.



    My initial training was with Ted McCoy down in (or up, depending on your orientation) cave country Florida. Ted was a brilliant instructor and many if not all of the lessons and idiosyncratic procedures I learned about diving the Meg and CCRs in general have pretty much stuck with me throughout this past year and on some occasions have been unsuccessfully attempted to be transferred over to the Defender.


    Comparing apples to sledge hammersÖ



    My meg is a 2.06 Apecs ECCR that was built in 2004 but had very low hours on it from a previous diver. Seriously, this thing was brand new practically speaking.
    The Defender is mostly made of New Old Stock hammerhead canister and head with the Defender electronics and the SG-1 Controller. Again I bought a used rebreather with relatively low hours and in great shape.



    I donít know if itís fair to do a direct comparison between the two units given the age and the technology, but in a hat tip towards the classic meg, I personally think that they can be compared against any rebreather on the market and hold their own very well. Also, itís the only other thing I know soÖ Iím going to compare them.


    Why did I get a new rebreather?


    I had very few reasons to look for a new rebreather. The Meg is pretty bullet proof machine and iím fairly certain it will last another 10 years without major issues. There were a few things I wasnít completely happy with on the Meg though and in the grand scheme of it all, they were fairly minor complaints but enough to stick with me a bit. These are the cons that I had listed on my Meg Vs XCCR/Defender spreadsheetÖ
    Cons:
    Turning on the unit.
    Non-Intergraded Deco
    Front mounted counterlungs?
    Becoming an instructor
    Replacement cost of batteries


    As you can see the cons of a Classic meg are pretty minor. I was told during my training that I would get annoyed with having to open the head to turn on and off the unit, especially while wreck diving and Ted was right on. Though many a diver out here in the Northeast diving their classics swear it doesnít bother them. The non-intergraded deco thing wasnít a big issue for me, but having to wear three large computers on my short arms was kinda a pain in the ass, not to mention having a secondary monitor clipped off to my chest. Replacing the megs batteries is also a minor inconvenience, but the frugal diver in me keep getting annoyed at spending $15 on 5 double AA batteries. (I did try to learn how to solder batteries, and that was a disaster and I very quickly realized how great of a deal $15 is to not have to do my own soldering)



    I wasnít sure and Iím still not sure if having Front-mounted counter lungs is a bad thing or not. I. very quickly, upon getting my Meg was able to score a set of some very sleek neoprene counter lungs and I felt it was a huge improvement over the standard lungs.



    Becoming an instructor was listed as a con for the meg but not for the process of having to become an instructor. I didnít know if the MEG market in my area could use another instructor. The Northeast has some pretty damn good instructors already including Becky and Andrew Driver and I would also have to own a Flagship rig (upgraded MEG 15) in order to teach them. Meaning that I was either going to have to upgrade my rig now, purchase a new 15 or look into a whole other rebreather.



    In comes the Defender. I wanted a rig that was easy for travel, modular, chargeable batteries, integrated deco and I was very curious about back mounted lungs. The path to instructor on the Meg and Defender is very similar.



    I purchased the Defender from Don Six in late April and he did me a huge solid and hand delivered it to Rob McGann in North Florida. A few days later I was in florida meeting Rob and my new CCR.



    The unit was in fantastic shape and aside from a few scratches and a couple of stickers that needed to be replaced was almost perfect. In a shopping bag that accompanied the rig was a few Don Six tools that he purposely built for the defender, including some ďCan openersĒ a custom made stand and Sorb canister cover.



    Building and breakdown:


    From what I can tell there is no officially printed build up checklist or manual for the Defender and buildup was done from the bottom up. Comparing this section to the meg is pretty easy since both rigs are very similar in this regard.


    Starting with the canister, I have a standard size Aluminum canister with an 8lb radial scrubber. There isn't a tremendous difference between the MEG and the Defender when it comes to the canister and both companies offer different size canisters to fill your diving needs. The standard MEG can and head do fit into a standard size carry on, where the Defender is just one inch too long to fit. Sub-Gravity does offer a mini can that would be perfect for the traveling diver and itís on the short list of things to order.



    Fully assembled the Defender is just a bit taller than the standard meg but that works out nicely for me since Iím short and have always been head heavy in my Meg. Trimming out on the Defender has been pretty painless but I have to constantly remind myself to add air to my wing rather than just drysuit in order to trim out better.



    My Defender did come with a custom built stand and I used it diving for awhile but after taking it off and trying it without, iíve come to enjoy the defender without it. Iím fairly short at 5í7 and never felt I needed the height on the rig in order to get in and out of it.



    The head of the Defender is sophisticated. Between the Bayonet connectors for the hoses, the O2 fittings and the Sub con connectors for the electronics the Defenders head just looks cooler than the more utilitarian Classic Meg. The hose connectors are worth their cost alone.


    Within the canister the 8lb radial scrubber sits on a short spacer and a few SHAM-WOW type towels. I was leery of the 8lb scrubber. At first I didnít think it would fit the type of diving I normally do which is 2-2.30 dives over a couple of days rather than one epic 14 hour dive.
    So far the 8lb scrubber has been working out great and has allowed me to maximize my sorb fills. I also prefer the less air space in the canister for trimming purposes.



    Filling the radial scrubber and locking down the lid has been a bit of a learning curve for me. With the Meg I used an Axial 5.5lb scrubber which filling was pretty straight-forward. Now, Iím far more paranoid with filling the radial scrubber. The biggest issue Iíve had so far is locking down the lid to close the scrubber. Itís a pain but the canister itself seems pretty solid and bullet proof.



    At first I was cursing at the bayonet connecter for the head to the canister since It felt like I needed the strength of 10 car mechanics with the forearm strength of Popeye in order to close and open it. Since my initial training Iíve become diligent about using a small amount of silicone grease during the build and any of the issues Ive had with the canister/scrubber/head connection are pretty much gone. Even getting the head off of the unit hasnít been much of an issue as long as itís greased up a bit. (Disclaimer, I donít know if Sub-Gravity recommends using silicone grease on the unit but itís what I have been taught to do with the MEG and itís worked pretty well so far.)



    Moving on with the unit the Sub-Gravity CCR wing is just awesome since it has the cutouts for hose routing. Just get one. Itís worth it.



    The Backmount Counter Lungs were for me the most anticipated change of gear. I had been super curious about them even before I bought the MEG. Front mounted lungs where one of the reasons I was originally hesitant about going the MEG route in the first place but I felt better knowing I could eventually get back mount lungs in case I didnít like the stock ones.


    When I spoke to Don Six about the unit before I bought it I asked him for what does he absolutely love about the unit? His response was that he felt the WOB is amazing and is one of the best units out there and blows away the rEvo in that regard. After my first dive on the unit at Blue Grotto I asked Rob McGann, ďDoes the Revo breathe like shit?Ē He said, ďNo, Why?Ē



    Being 100% honest, My first week or so with the BMCL I hated them! I was having some serious doubts about sticking with the BMCL. It felt like I was taking a lung function test on each breath. Donít get me wrong, having the MAVs are awesome. They feel good, super easy to use and they allow for adding off board gas. I love where they sit and getting to my chest d-Rings is cake.



    I was advised to give it time, and 100% honestÖ 20 hours laterÖ I donít even notice it being any harder or easier than the MEG. Now I LOVE the BMCL. I think I can get my chest cleaner by moving some things here and there, I did remove my SPGs and went to button gauges pretty quickly after bringing the unit home and added some bungee to hold the MAVs away from the chest D-rings.



    My only real complaint with the lungs are, de-watering them. After about an hour and a half I get really bad gurgling from lung-butter build up (My terms). Getting most of the spit back to the lungs is easy by forcefully blowing into the hose and getting slightly heads up but once back in a horizontal or heads down position it comes right back. With my limited experience even trying to do a dil flush to de-water it doesnít help too much since water can come back into the lung if not done properly.



    Overall, I really do enjoy the BMCL but there definitely was a time period where ordering OTSCL was on the list for things to order. They have since been removed and if I keep my MEG, iíll be adding BMCL to the unit also.



    TO BOV or not to? I spent about 100 hours on my MEG without a BOV. I read all the forums, pros and cons on having one vs not having one. Now that I have oneÖ Itís pretty Fíning awesome! Bailout drills, dil flushes, adding Dil upon descent without an ADV is cake and just being able to take a couple mouth watering breaths is fantastic. Itís a bit heavier and I have been playing with a couple different mouthpieces to find the most comfortable one to use for long periods but I donít think I would go back to not having a BOV.



    Equipment wise, the biggest difference between the MEG and Defender would be the Primary electronics. For me, having integrated deco, became a big deal after diving the MEG awhile. At first the SA perdix was fine, then I added the backup SA perdix. So two Shearwaters, plus a Primary controller and a secondary clipped off it just seemed excessive.



    Having the real estate back on my arms was awesome. On my left is the SG-1 and the secondary is a Petrel 2. Both have Deco and use similar algorithm even though the SG-1 is far more conservative (or at least doesnít clear deco the same way the Shearwater does).
    The SG 1 is a nice computer and fairly easy controller but it isnít perfect and if you are coming from a shearwater controller or the APECs it can be frustrating coming across glitches. Any issue iíve had so far with the SG-1 has been reported to Sub-Gravity and apparently they are all fixed with the next software/firmware upgrade and are being field tested now.



    One complaint that I heard from a very experienced CCR diver was that the HUD was too bright on the Defender. I disagree completely, I love the light level on it. One of my issues with the MEG was that I couldnít see the green light diving in the Northeast since the light blended in. I have no issues with the HUD brightness as of now.



    Lastly with regards to the actual CCR, the Metalsub brackets are easily, hands down the best mounts on the market. Iíve used the Tiger mounts, reef mounts, Northern divers, silly cam strap contraptions, I was personally talked out of the shadow mounts, and the Metalsub is bar far my favorite. If the MEG stays around, Iíll be selling all the tiger mounts I own.

    Actually diving the unitÖ



    This is where the unit shines IMHO. Diving the unit strictly as a eCCR letting the computer and solenoid take care of maintaining the set point, I think it handles the job better and tighter than a Meg. There is a philosophical difference between how the MEG and Defender handle set point control or at least the way it was explained to me by a CCR mentor. The MEGís set point was the minimum it would go down to, where the Defender it was the maximum. Iíve noticed this in action when you watch when either unit will fire in some O2. It seems like the Defender rounds up or down while averaging the PP02 readings and a 1.19 is close enough to 1.2 where the solenoid wont fire, where as on the MEG the solenoid would be going off every 4 seconds (on my unit) until all the cells are over 1.2.
    Realistically, I donít think its a huge deal for either unit it was just different. As I monitored my PP02 readings it would give me pause thinking the solenoid has failed on the unit and then it clicks once it drops another point.


    Training:

    I did my crossover with Rob McGann. I chose to do it with him since any conversation I ever had with him was honest, straight-forward and without reciting any sales pitch or portion there of. Rob also has a wealth of experience diving wrecks in the ocean and diving CCR from a boat which fits into the majority of diving I do.



    His class was the perfect combination of casualness and skills/drills. I had plenty of time to ask questions, build the unit, discuss pros and cons of each part and most importantly had plenty of time in between each skill, drill or emergency to build comfort on the unit. Not to mention his cooking is fantastic, his wife is one of the nicest people in the world and they are some of the easiest people in the world to have a conversation with. I mean, he is also a really awesome diver and all of that but I assume everyone already knew that. It was really cool getting a whole new perspective on CCR diving from another experienced diver/instructor.


    In short, Iím keeping the Defender and Iíll be getting an XCCR in the near future. Iím very happy with how everything turned out with the unit and I think iím going to have a really awesome time with it gaining experience.

  2. #2
    RBW Member hbm is on a distinguished road hbm is on a distinguished road hbm's Avatar
    Join Date
    Nov 2010
    Location
    Pa
    Posts
    25
    Not yet

    Re: One month with the Sub-Gravity Defedner

    At first I was cursing at the bayonet connecter for the head to the canister since It felt like I needed the strength of 10 car mechanics with the forearm strength of Popeye in order to close and open it. Since my initial training Iíve become diligent about using a small amount of silicone grease during the build and any of the issues Ive had with the canister/scrubber/head connection are pretty much gone. Even getting the head off of the unit hasnít been much of an issue as long as itís greased up a bit.

    Somebody who looks a lot like Rob taught me to put some positive pressure in the loop and that way you can get the head off with the strength of just your little finger once you un-lock it.


    My only real complaint with the lungs are, de-watering them. After about an hour and a half I get really bad gurgling from lung-butter build up (My terms). Getting most of the spit back to the lungs is easy by forcefully blowing into the hose and getting slightly heads up but once back in a horizontal or heads down position it comes right back. With my limited experience even trying to do a dil flush to de-water it doesnít help too much since water can come back into the lung if not done properly.


    I used to get the gurgling as well and found most water wasn't from me but entered the loop from outside. I put a little silicone on the T's and BOV bayonet and the problem is gone. It's now absolutely silent. When ever I do get a little water (loose lips) I grip the downstream hose and contract it (to make it smooth inside) while I roll left. Dewaters well.


    I'm brand new to CCR and have 73 (93 hours) non training dives on the Defender and the thing has been great. I download the petrel and compare my depth profile (Jagged tooth) to the PO2 profile (flat as can be). I always marvel how this thing holds set point. I don't know what HUD holder you have but I can twist mine around pretty easily to get it in the right position for the light conditions. Your right about the brightness, I did (tried) a lights out practice with a buddy in Peacock and it lit the passage up.

  3. #3
    RBW Member goodlifedivers is an unknown quantity at this point goodlifedivers's Avatar
    Join Date
    Jul 2014
    Location
    Oyster Bay
    Posts
    17
    None

    Re: One month with the Sub-Gravity Defedner

    Yeah the positive pressure trick is a cool one. I found once I greased it up it came off without any issues. The complaint was more about the twisting action it takes to open and close it.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts