The Velocity testing found that, in fact, deep stall entailed very low decent rates. They very likely are not survivable on land, but they certainly are at sea since more than one person has (with the old style Velocity seat, much like the Cozy). To quote the test pilot "Amazingly, Carl says that he could stick out a hand and feel hardly any air rushing against it as the Velocity descended ever nearer the ocean of St. Augustine. Although he was wearing a 'chute, he ultimately chose to ride the airplane down... and suffered no injuries." At high speeds water is only slightly less harmful than land. They reckoned that the descent rate was from 15-20 MPH. For reference 20 MPH is about 30 fps.
Sorry guys it was a Velocity
Found this reference but nothing on a detailed accident report