Could the US Navy have tested magnetic detonators in more regions given the size of the United States and its territories?
Short answerYes, but American ships did not operate across as many regions as routinely as Royal Navy ships, so Britain accumulated a broader body of environmental data despite limits in both test programmes.
NotesThe US Navy could have tested equipment in more regions, but American ships had fewer routine reasons to visit such a wide spread of locations. Royal Navy deployments repeatedly generated data from different magnetic environments. Both services still imposed limits on formal testing. The British advantage came less from a flawless test programme than from the breadth of ordinary global operations available to inform it.