I am looking for a balanced diaphragm regulator. I am also looking for a very reliable, durable regulator and was told that Sherwood provides just that. But, on the website, there is very little/no information about whether the regulators are diaphragm or piston. I will be diving in Fiji, and although the water is very clear and warm, I want a regulator that will not pose any problems over the course of two years. I plan to be in a very secluded area with no easy access to any LDS, SCUBA diving nearly every day. Currents may pose an issue, and since I will be diving year round doing reef studies, sediments may be a concern during the rainy season. Any information or advice would be very helpful.