reefrat
Contributor
My wife and I finally had a chance to try out two new Hollis 500SE second stages at Cozumel last week. The weather was not great and we only managed 8 dives each but it was enough to get a good impression of the units attributes. Everything here is just my opinion and based on personal observation or subjective testing.
Firstly, the 500SE second stage I used was attached by the factory maxflex hose to a Hollis DC3 first stage instead of the usual DC7 because I needed a yoke instead of DIN and none were available in the DC7 at the time, I do not believe this affected performance in any noticeable way.
The reg was set up at the local Hollis diver dealership and tested to ensure it was correctly tuned for best breathing.
Gas used for the whole trip was normal air, the daily maximum depths were around 90 to 100 ft. and as usual for Cozumel all dives were drift dives.
Impressions:
The second stage body has a fairly solid, quality feel in the hand and it looks ultra-modern and attractive (to me). Without going into too much detail the biggest difference I can see between this and previous side valve servo activated regs is that the exhaust valve is separate from the main diaphragm and is positioned on the front aspect of the body. An exhaust shroud deflects the bubbles quite well and far out to the side when used in a horizontal face forward position in the water.
The servo activated downstream valve unit is easily removed from the reg body by unscrewing (by hand) a locking nut on the hose end and then sliding the O ring sealed valve unit out- still attached to the hose. The all metal valve is quite neat locking and appears to have been nicely machined.
The mouthpiece is an orthodontic type and works OK but I prefer custom molded types and so fitted a Type 5 Seacure (the size intended for Poseidon regs) and this combination worked extremely well.
NB: When I hereafter compare the 500SE to conventional regs I am referring to the most common second stage type seen from most manufacturers- round body with main diaphragm in front, exhaust valve central and rearward.
In the water:
I was pleasantly surprised to find that the 500SE breathes dry, as dry as any I have ever used and dryer than most conventional types. There was occasionally a tiny dribble of water that was easily and instantly ejected by exhaling with a slight tilt to the left and face down.
Side exhaust regs like this are often touted as better for keeping bubbles away from the face area and IMO this is partly true. I would rate the bubble interference on the 500SE as about the same as a Poseidon Odin, which is to say that its about as a good as a conventional second stage with a wide exhaust tee and therefore better than average.
Ease of breathing: Some servo regs have been associated with a slightly higher initial cracking pressure on inhalation followed by a gush when the gas is delivered. I am happy to report that this is not the case with the 500SE and in fact it is a very smooth, easy and natural breathe, if you are familiar with other high-end balanced second stages such as the Scubapro s600, Aqualung legend or Atomic offerings you will find it very similar, and that is praise indeed!
The servo valve is apparently the same as used in the old Oceanic Omegas and some owners have reported long trouble free use of these so the outlook as far as longevity and reliability seems promising.
The exhalation effort seems to be very low and I feel it is about the best I have ever used.
Overall the 500SE is a pleasure to breathe, however there was one issue and it was exactly the same on both 500SE second stages that I tried so it may be typical of all- I cant be sure. When inhaling very slowly and gently the valve delivered gas perfectly, the same could be said for a rapid full inhalation. But there was a point somewhere between the two where the delivery was accompanied by a slight harmonic buzzing or humming in the valve- it did not affect the breath but it marred what would have otherwise been a perfect performance for me! Note that this is not a stuttering that can occur with some high performance regs in shallow water, it is more subtle than that, but it is noticeable nonetheless!
I found that the 500SE breathed much the same in all orientations, face up or down and anywhere else- it seems far less affected by position than any other reg I have tried, once again it was also very dry during these informal tests.
Conclusion:
Its a keeper for me!
For the general performance I can overlook the harmonic buzzing on some inhalations although that may not be the case for other people. Would I rush out to sell my high-end Scubapro or Legend that I am perfectly happy with to buy one of these? Probably not!
But it is a really neat and interesting second stage that works extremely well and if not for the occasional harmonic buzzing I would think it was the best currently available.
PS. my wife decided to change back to her Atomic B2 after 2 dives- she liked the 500SE but was just too comfortable with her old reg to change, if anyone is interested I will sell her 500SE second stage (no hose) for $150 plus shipping- it is absolutely "as new"!
Firstly, the 500SE second stage I used was attached by the factory maxflex hose to a Hollis DC3 first stage instead of the usual DC7 because I needed a yoke instead of DIN and none were available in the DC7 at the time, I do not believe this affected performance in any noticeable way.
The reg was set up at the local Hollis diver dealership and tested to ensure it was correctly tuned for best breathing.
Gas used for the whole trip was normal air, the daily maximum depths were around 90 to 100 ft. and as usual for Cozumel all dives were drift dives.
Impressions:
The second stage body has a fairly solid, quality feel in the hand and it looks ultra-modern and attractive (to me). Without going into too much detail the biggest difference I can see between this and previous side valve servo activated regs is that the exhaust valve is separate from the main diaphragm and is positioned on the front aspect of the body. An exhaust shroud deflects the bubbles quite well and far out to the side when used in a horizontal face forward position in the water.
The servo activated downstream valve unit is easily removed from the reg body by unscrewing (by hand) a locking nut on the hose end and then sliding the O ring sealed valve unit out- still attached to the hose. The all metal valve is quite neat locking and appears to have been nicely machined.
The mouthpiece is an orthodontic type and works OK but I prefer custom molded types and so fitted a Type 5 Seacure (the size intended for Poseidon regs) and this combination worked extremely well.
NB: When I hereafter compare the 500SE to conventional regs I am referring to the most common second stage type seen from most manufacturers- round body with main diaphragm in front, exhaust valve central and rearward.
In the water:
I was pleasantly surprised to find that the 500SE breathes dry, as dry as any I have ever used and dryer than most conventional types. There was occasionally a tiny dribble of water that was easily and instantly ejected by exhaling with a slight tilt to the left and face down.
Side exhaust regs like this are often touted as better for keeping bubbles away from the face area and IMO this is partly true. I would rate the bubble interference on the 500SE as about the same as a Poseidon Odin, which is to say that its about as a good as a conventional second stage with a wide exhaust tee and therefore better than average.
Ease of breathing: Some servo regs have been associated with a slightly higher initial cracking pressure on inhalation followed by a gush when the gas is delivered. I am happy to report that this is not the case with the 500SE and in fact it is a very smooth, easy and natural breathe, if you are familiar with other high-end balanced second stages such as the Scubapro s600, Aqualung legend or Atomic offerings you will find it very similar, and that is praise indeed!
The servo valve is apparently the same as used in the old Oceanic Omegas and some owners have reported long trouble free use of these so the outlook as far as longevity and reliability seems promising.
The exhalation effort seems to be very low and I feel it is about the best I have ever used.
Overall the 500SE is a pleasure to breathe, however there was one issue and it was exactly the same on both 500SE second stages that I tried so it may be typical of all- I cant be sure. When inhaling very slowly and gently the valve delivered gas perfectly, the same could be said for a rapid full inhalation. But there was a point somewhere between the two where the delivery was accompanied by a slight harmonic buzzing or humming in the valve- it did not affect the breath but it marred what would have otherwise been a perfect performance for me! Note that this is not a stuttering that can occur with some high performance regs in shallow water, it is more subtle than that, but it is noticeable nonetheless!
I found that the 500SE breathed much the same in all orientations, face up or down and anywhere else- it seems far less affected by position than any other reg I have tried, once again it was also very dry during these informal tests.
Conclusion:
Its a keeper for me!
For the general performance I can overlook the harmonic buzzing on some inhalations although that may not be the case for other people. Would I rush out to sell my high-end Scubapro or Legend that I am perfectly happy with to buy one of these? Probably not!
But it is a really neat and interesting second stage that works extremely well and if not for the occasional harmonic buzzing I would think it was the best currently available.
PS. my wife decided to change back to her Atomic B2 after 2 dives- she liked the 500SE but was just too comfortable with her old reg to change, if anyone is interested I will sell her 500SE second stage (no hose) for $150 plus shipping- it is absolutely "as new"!
