How unfavorably would the Royal Navy have viewed a real Atlantropa project in 1935?
Short answerExtremely unfavorably, because damming Gibraltar would devastate the Mediterranean and transform its ports and naval geography.
NotesAtlantropa proposed reclaiming land and generating hydroelectric power by reducing Atlantic inflow through Gibraltar. Further dams between Sicily and North Africa would lower the eastern Mediterranean, with a reduction of about 200 metres envisaged. Such a change would disrupt the geography on which the Royal Navy and the Italian, Turkish, and Soviet navies depended. The feared environmental consequences include spreading arid conditions northward into southern Europe and devastating adjoining parts of Africa. Settlements on reclaimed land would also face catastrophic flooding if a dam failed.