Pontius,
One mile call was at one mile for us angry palm trees: speed was fairly irrelevant. Ours was 200 feet, 100 knots
There was an 'at least' 2 minute call required from the Controlling Unit, "Stand-by Dustbin, 2 minutes, Surface Zero Position", then the calls as posted earlier by Data-Lynx. We were further taught to go max chat after drop, with doors and windows open to reduce overpressure. At 200 feet overwater with a bucket of sunshine sinking slowly through the depths behind us, and a bit of a surface effect to be expected soon
Strangely, the Pilot was responsible for the one mile "Beware, Beware" call, but the observer made the "Dustbin, Dustbin" radio broadcast when Pressing to Release.