as far as what the proteus does, it allows any payload to be stabilized to tolerances that were once the stuff of science fiction. six tenths of an inch in 30 ft seas is just astonishing to me.
the practice of "down-hole logging", to gather data from inside a well using various monitoring devices on a wireline, is one such application for proteus. this is what they did onboard the SODV's, or the scientific ocean drilling vessels. google that!
but these active heave compensators will have many more uses, including deployment of ROVs, delivery of construction payloads, etc.
with so much money riding on the line, and the very real risks of losing days, weeks, or months on a project due to rough seas, i can imagine we'll be selling a lot of proteus units in the future.