Parma's barges and the fatal coordination gap

The flat-bottomed transport barges were not warships and could not fight their own way out of Dutch-controlled waters. They required the Armada to clear English and Dutch forces and then escort Parma's army across the Channel. Medina Sidonia appears to have expected Parma to meet him at sea, turning a misunderstanding of basic capabilities into a severe timing problem. Even after a successful crossing, the invasion force would face the incompatible demands of concentrating for battle and dispersing to control England. A Protestant Scotland might also intervene against Spanish-controlled England, creating another organized opponent. Smaller detachments sent across hostile country would then become vulnerable to local ambush and defeat.