Comparative sea-floatplane doctrine remained a research gap

Where can a reader find a cross-navy comparison of Second World War sea-floatplane doctrine?

No direct comparison was known; Alex Howlett's First World War seaplane work was the closest specialist starting point.

No direct cross-navy comparison of Second World War naval floatplane doctrine was known. Alex Howlett's work on First World War seaplanes is the closest specialist lead offered here. The recommendation points to established scholarship on the earlier period while leaving the later comparative question open. It preserves the limit of the available knowledge instead of presenting the earlier study as a substitute.