How would the navy develop if all Seventeen Provinces had broken from Spain during the Eighty Years' War?
Short answerIt would probably resemble the historical Dutch system on a larger base, while spending more resources on land defence and continental frontiers.
NotesAn independent union of all seventeen provinces would still build its seventeenth and eighteenth-century strength around merchant shipping and provincial admiralties. More people and resources could support a larger navy, perhaps with some admiralties combined. The enlarged state would also face heavier land commitments and would lose some of the defensive advantages enjoyed by the historical Dutch core. Its territory in modern Belgium, Luxembourg, and Germany would create strategic depth while exposing it to French and continental pressure.