A body has been recuperated from the destruction of the plane which slammed with Cardiff City footballer Emiliano Sala and pilot David Ibbotson ready.
The Air Accidents Investigation Branch said expert temporary workers joined the activity in “testing conditions”.
It was done in “as stately a route as would be prudent” and the men’s families were kept refreshed all through, it said.
The destruction of the plane, which evaporated two weeks back over the English Channel, had been found off Guernsey.
The Geo Ocean III, the pontoon conveying the body, landed at Portland Port in Dorset on Thursday morning.
The Piper Malibu N264DB was on the way from France to Cardiff, after the 28-year-old Argentine striker made a speedy outing back to his previous club Nantes two days after his £15m exchange to Cardiff was declared.
Mr Ibbotson, 59, from Crowle, North Lincolnshire, was at the controls when the flight lost contact with air traffic controllers on 21 January.