There has been some questions and comments about the number and location of ports.
Port location and quantity is one that I knew from the beginning that there was no way to please everyone or every configuration. There were also major trade-off consideration with weight and fit if I added more material to add more ports.
Keep in mind that ports take space and volume from the inside of the body. The body on the Argonaut is both the first and the second stage so it is hard to compare it to a modern first stage with several LP and HP ports.
At the end I decided that 3 LP ports and one HP port was the minimum required to meet the largest numbers of divers. But just as important was the added flexibility to add extra ports.
A lot of divers frown on the use of adapter. But most adapters are actually very reliable and I actually designed the end port so that the adapter would actually look as an intentional part of the design.
I actually always use the low profile 70 degree elbow shown below on the left LP port to route my BC inflator hose low against my shoulder. That fitting accomplisher my preferred port angle at a much lower machining cost and headaches than if I would have incorporated it into the design. To tilt the port would have made the machining much more complicated.
http://vintagedoublehose.com/index.php? ... ry=9965573
I also use the same LP swivel on the top-right port to point my drysuit inflator hose down. Not everyone needs a drysuit hose, but I knew from the beginning that I had to incorporate one and that an elbow was the best solution to keep the low profile and keep the weight down.
HP swivels are also available with one or two HP outlets. They can add an HP port or just reroute the HP hose. The swivel fits on the bottom left of the regulator. It should look like part of the regulator and it would be hard to see when it is mounted on a single or double tanks.
The drawing below shows a cross section of the Argonaut main body and some views with all the internal hidden lines (shown in light blue). The hidden lines is like a see through drawing. You can see the ports (including the threads), the volume for the first and second stage. There is virtually no unused extra volume to actually add anything without making the body bigger.