How about the SF2 Rebreather?

[W W Meixner]

How does SF2 Rebreather compare to other Rebreather?
Though I'm not a Rebreather diver, I wonder about CCR.
I do not know which model is good or bad, and I do not know which model to choose.

please , reply me

Jeong...

Lots of good responses have been posted...

Without getting into specific units as that's a topic that's widely debated...ask yourself the following...

What are your plans...for now and for the future...is after sales service and instructor training on your ''short-list units'' readily available...the closer to your specific area the better...as more distance translates into more money...

Are you willing to get involved with lots of pre/post unit checking...cleaning...maintaining...are you willing to get joined at the hip to ''checklists''...are you willing to become self reliant on some of the repairs/replacements...

Some manufacturer distributors will only make parts available on an ''as installed'' basis...meaning parts are restricted...for which you can ad high mark-up...and upwards to $100. per hour for labor...and return shipping...

Longevity and continued support is important...although no manufacturer is going to tell you that they plan on closing up shop in six months...the rate of manufacturer failure in this sector of the industry is high...do your research...look for as much product stability as you can...

Do you have someone of like-mind to dive with...there's not much point of you diving with a rebreather and your buddy diving with an AL 80...

Are you prepared for high initial expense...and continual ''higher than usual'' expenses for consumables...service parts...spares...and shipping your unit back and forth to a service center if one is not close...

Depending on your residence proximity to your nearest supplier...because of size and weight...it may be as expensive to get a keg of absorbent shipped as the keg is worth...

Ask all the questions...based on your wants but more specifically on your needs...get your hands on everything you can that's readable...view all the videos...and there are lots on all the units...

As has already been mentioned...get yourself plugged into as many ''try-dive'' sessions as you can...

Believe me...it's a wonderful adventure...but like everything else...not for everyone...

Dive Safe...

Warren

 

[Slamfire]

The SF2 is a fantastic unit. It’s dead simple, trims easily, easy to build, and has several very nice features. The WOB issues are significantly overstated. I can breathe on it in any orientation. Head up and head down (totally vertical) are less enjoyable than in trim, but I haven’t had any issues to where I’d even consider going off the loop.

In your opinion, how does it compare it to the rEvo? Particularly with WOB. You used to dive a rEvo, right? Or am I imagining things?

 

[rjack321]

Pros:
Nothing dewaters better, period

Whatcha talking about willis?
Sorry pretty much any CCR with over the shoulder counterlungs is going to be more flood tolerate and easier to dewater than the SF2 with an OPV in the butt of a tube that is almost impossible to reach for most people with normal arms. At the very least you have to go vertical.

 

[broncobowsher]

A couple years ago I was in the market for a rebreather. Had a chance to get into DEMA and see just about all of them in person. I had done a lot of online research ahead of time. It is amazing how things are different when you actually see them in person. Stuff near the top of the short list fell completely off. Stuff I almost never heard of started looking really good.

As for the SF2, I never dove it but just looking it over I was more impressed in person then on paper. It was one of the few that I liked better after seeing it in person. Looked well thought out and built. If I remember right, heavy, fairly large (long), single counterlung. Fairly low number of failure points. I would think of it more of a local dive rebreather and not a travel style. Sidemount being a strong option on it.

I picked a revo as they are a bit more common in my area (not the most common, but not unheard of either) and they are lighter/more travel friendly. For myself, how I want to use it, where I am at, it is a good choice. For someone else, with different needs, in a different place, maybe not the best choice. I will not me running any tight caves with it.

No matter which one you look at, a different rebreather will be better at something. But the SF2 isn't a runaway rebreather. That is one that you run away from when someone brings one by. You are not dealing with a Hollis Explorer.

As for traveling to learn to use it, with something this specialized that is generally a normal item. Unless you are in an area that has everything at your finger tips (Florida) you can expect to travel. Looks for a good instructor, not a convenient one. When doing my shopping I was in a local shop and the owner gave me the line of "I'll be teaching these shortly, just as soon as I get enough hours in on it". He only owned if for a month or two. So he was a complete novice on it as well, wanting his first student. This is like going to a doctor who gets to operate on his first patient. He may have assisted, or watched it done a few times, but do you really want to be the first one he does?

 

[Dsix36]

I currently dive a rEvo and to be honest, it has treated me extremely well and is nothing but dirt simple to maintain and dive. I mention this only because the SF2 is the only other unit I have ever seen that rivals the simplicity and ease of maintenance. OK, hell it wins the contest.

I did a pretty thorough orientation and try dive on one thanks to James Draker and found it to be damn friendly to dive. The WOB is not perfect in all positions but is is completely manageable and not near as terrible as some would lead you to believe. Floating in the water, vertical, at the surface will be the worst you ever encounter.

The only reason that I have not switched to the SF2 is the lack of funds right now. A SF2 is definitely in my future though.

 

[JohnnyC]

The SF2 is light as hell actually, and travels super easy because it's mostly carbon fiber. Put the head and scrubber in your carry-on and it's super light. Compare to a Meg or a JJ or something and it's pretty much a brick/feather comparison. The only issue is that it's long due to the head latching mechanism which negates really taking it apart for small packing. It's a holdover from the PSCR that it was based on, so unfortunately it is what it is. In theory, you could cut off the locking arms and replace them with latches on both the upper tube and CL and lower sections to get it to pack down smaller, but that's some work I'm not keen on doing as you're screwing into the carbon fiber. A shorter lower section could also make it smaller, but from what I understand, it's only a special order option.

The rEvo's are only really travel friendly if you carry it on like a backpack.

As for the rEvo, I've only try-dived one. The ADV was ATROCIOUS and there's no easy way to dewater it. I was not a fan. The WOB was fine, but the version I tried was so chock full of electronics that it was a pain. I get that they want to be super redundant, but at some point it's just too much. Getting a more stripped down unit is much more appealing to me in that regard. I understand that the ADV can be tweaked, but I don't want to have to screw with it that much. The dual scrubbers are a cool idea.

As for dewatering an SF2, it practically dewaters itself, and was WAY easier to dewater than my Meg, even with neoprene lungs. Either arch your back and hit the dil MAV, or if you're over minimum loop volume, just exhale sharply and it blows it all out. You don't touch the OPV at all. Really the only reason it is a tunable OPV is because it's a COTS drysuit dump instead of a custom part.

 

[Jeongmin Ha]

I have been diving with only air tanks so far.
Future plans will dive like I have done so far.
There is no special plan.

I learned a good chance to learn sf2 rebreather.

However, when I learned one unit, I knew that I had to start again to learn another unit.

Also, because a lot of money was generated, I was worried.

So when I started, I wondered which unit to choose.

I wondered what other divers think.

Thanks to all the people who commented.

 

[J J]

Just in the name of idle curiosity, how's the o2ptima compare with the others mentioned here.

 

[broncobowsher]

Just in the name of idle curiosity, how's the o2ptima compare with the others mentioned here.

That is called a hijack. Take a thread about one thing and side track it into something else for yourself. A fairly low thing to do. Take an extra minute and start a new post. It isn't that hard and keeps this one focused.

Thank you.

 

[J J]

the OP's original question was:

How does SF2 Rebreather compare to other Rebreather?
Though I'm not a Rebreather diver, I wonder about CCR.
I do not know which model is good or bad, and I do not know which model to choose.

Is he not asking about how it compares to any model? My intent was not to hijack, but to find out why no one was talking about some of the other rebreathers i'd heard about. Perhaps I miss read his question.