To answer your question---the cameraman would simply get out and swim.
Gordy, the risk is getting entangled in the arm and not getting out or inability to release the arm whilst in the water. Exposure over the water in the video wasn't long, the rehearsal was longer.
A cameraman drowned a few years back because he became entangled in his camera mount when the Cessna he was filming from made a controlled ditching, but 3 other persons on board simply got out and swam.
Like that incident, this video is a worthy idea shot on a limited budget with willing participants, this is a common mix of factors in helicopter accidents involving filming. Just like the one two weeks ago shooting the skateboard competition. No question the Grand Rapids shoot was better planned than most, which makes me more curious as to PPruners' opinion if the rehearsal and shooting flights could have given the cameraman a greater safety factor.ie a safety boat? floats? helmet? ect
Mickjoebill