Page 1 of 1

Aqualung Aquarius Limitations

Posted: Fri Jan 27, 2017 6:26 pm
by hunterkz
I have a couple mid 70's Aquarius regulators that I rebuilt and are working great. I was wondering if you guys think that there are performance/depth limitations for these. I like to dive with these as one of them was my first regulator and has a special place in my heart. My teenagers both dive and I was wondering if these were suitable for deepish dives say to 130 feet of so for them to use.
Thanks

Re: Aqualung Aquarius Limitations

Posted: Fri Jan 27, 2017 6:42 pm
by Herman
Welcome to the board.
For rec diving, I don't see any issues with using them as long as they are properly maintained. I wouldn't ice dive or cave dive with them or go over rec diving limits with them but otherwise I would dive them.
Bryan (owner of VDH) has service kits available and the Early US Divers manual has the service info in it.

Re: Aqualung Aquarius Limitations

Posted: Fri Jan 27, 2017 8:22 pm
by luis
If they have been maintained, these regulators are very simple and therefore very reliable.

Just be aware that their first stage is a non-balanced piston regulator. That in itself is not an issue and it actually has a side benefit from a safety point of view. They get harder to breath as tank pressure drops. If the diver is aware of that, it can become a nice warning system that will not let you forget that air pressure is going down, with good advance warning.

The only concern with the non-balanced first stage is that the design incorporates a relatively small volcano orifice in the first stage. The small orifice design is used to reduce the amount the intermediate pressure (IP) changes as the tank pressure drops. The undesirable side effect is that the smaller orifice can restrict the flow rate under certain circumstances (Very deep, hard work, low tank pressure).

The first stage orifice size is designed to be large enough to accommodate the flow rate required by most divers at recreational depths and with a reasonable work load. The flow rate may feel restrictive as depth increases (probably well past 100 ft) and if it is in combination with high work load increase (from swimming into current, etc). If at the same time the tank pressure is lower, the increase work of breathing can become very noticeable.

I am sure the Aquarius has been to 130 ft a number of times and if the diver is not working hard, etc. any work of breathing increase probably went un-noticed.

Just be aware of its limitations.

Re: Aqualung Aquarius Limitations

Posted: Fri Jan 27, 2017 10:16 pm
by hunterkz
Thanks for the input. I did get rebuild kits here for both at VDH and tuned them for nice easy breathing at the surface. I upped the IP to 143 on them in hopes for a little bit easier breathing. Cracking effort is perfect (on the surface) and when it warms up I will take them out for a little treasure hunting up here in NY. I have to keep busy during the off season so I rebuilt all the regs I currently own. Mainly I will be using them for 10-80 ft diving and I might get another to use as a pony bottle reg (currently a sherwood brut). Great site and all the posts I have read are right to the point and accurate. People are friendly too. Thanks again for the advice. Now I am getting interested in a double hose but boy they can fetch a pretty penny for some of them.

Re: Aqualung Aquarius Limitations

Posted: Mon Mar 20, 2017 8:55 am
by georgeaustin
I don't know about anyone else but there's no place I'd rather be than swimming against a hard current at 130+ ft with low tank press. and an unbalanced little regulator ;-) Now that's what I call two fisted skin diving adventure!

Re: Aqualung Aquarius Limitations

Posted: Mon Mar 20, 2017 8:57 am
by georgeaustin
hunterkz wrote:Thanks for the input. I did get rebuild kits here for both at VDH and tuned them for nice easy breathing at the surface. I upped the IP to 143 on them in hopes for a little bit easier breathing. Cracking effort is perfect (on the surface) and when it warms up I will take them out for a little treasure hunting up here in NY. I have to keep busy during the off season so I rebuilt all the regs I currently own. Mainly I will be using them for 10-80 ft diving and I might get another to use as a pony bottle reg (currently a sherwood brut). Great site and all the posts I have read are right to the point and accurate. People are friendly too. Thanks again for the advice. Now I am getting interested in a double hose but boy they can fetch a pretty penny for some of them.
If you can be patient, you'll eventually source a competent DAAM for around a hundred bucks - good luck!