Most will recognize that KISS is the acronym for "Keep it simple stupid."
The phrase for which the acronym KISS came from was originally started by Kelly Johnson, lead engineer at the Lockheed Skunk Works - creators of the Lockheed U-2 and SR-71 Blackbird spy planes. The idea was not to imply that the engineers he was working with were stupid, but just the opposite in that his belief for most systems to work best in the field under real-world conditions, their design should be kept as simple as possible instead of complex.
The concept goes even further back to one of histories most renowned inventors, Leonardo da Vinci, who emphasized "Simplicity is the ultimate sophistication,” noting that the ultimate goal in design should be the avoidance of unnecessary complexity.
This is a viewpoint that was not lost on KISS Rebreathers first designer Gordon Smith, or on current CEO Mike Young, particularity with regards to life support equipment that will be taken underwater. And for something to be truly called “Expedition Grade” it needs to be not only robust but also easily serviceable in the field. After all, there are no repair shops or FedEx drop boxes when you are deep in a cave, in the middle of a jungle or out sea on a desert island.
It is important to remember that everything eventually fails, and this is certainly true for any product that is taken underwater. With this mind, KISS rebreathers are designed to be durable, yet easy to assemble, dive and learn how to use.