Pelagic Computer software (Aeris , Genesis, Oceanic, Sherwood, Tusa, Aqua Lung etc.)

[scubadada]

Craig

First, I did indeed mix up the Aeris Atmos (which I used to own, before it broke) and the Sherwood Amphos, which I'm planning to buy. Your comments were very helpful, and I do understand that Pelagic makes both Oceanic/Aeris and Sherwood computers. But on a separate thread on this board an executive at Sherwood described the Amphos thusly: "The computer is made by Pelagic Pressure Systems and although it is similar to some of the ones made by Pelagic for Oceanic or Aeris the Shwerwood Amphos it is based on our famous Wisdom 3 platform." In short, he says "similar" but he doesn't seem to be saying identical. I've seen specs on the Oceanic algorithm that describe it as Pelagic DSAT "Spencer/Powell" whereas the Sherwood states it is Pelagic DSAT "Modified Haldanean". I really have no idea if there is or isn't an appreciable difference. My dive master puts it this way: you need a computer that will let you dive 50-55 minutes at 50 feet.

All Sherwood computers are manufactured by PPS and all of them are "similar" to Oceanic/Aeris models. The Amphos is similar to the Oceanic Atom 2/3.1 computers. The Amphos is 2 gas, the Atom 2 was 2 gas and the Atom 3.1, 3 gas. It appears Oceanic is not manufacturing the 3.1 any longer, though it is still available, and it had replaced the Atom 2. If you look at the Amphos manual you will see that the DSAT decompression algorithm is described exactly the same as Oceanic and the NDL table is exactly the same.

Oceanic is dual algorithm and runs DSAT and PZ+. Sherwood runs DSAT only. Aqua Lung runs PZ+ only. As pointed out by Tursiops, DSAT give 81 minutes at 50 feet on air, PZ+ gives 65 minutes, maybe your DM meant 60 feet, where DSAT gives 57 minutes and PZ+ only 48.

Good luck in your dive computer purchase