Reasons for Failure: English tactics, the weather, Spanish mistakes
English Tactics: skilled commanders like Franics Drake, use of fireships, constant bombardment of cannons at the Battle of Gravelines, faster ships
Weather: ferocious storms in the North Sea, ships ran out of supplies, men unable to sail due to exhaustion/illness
Spanish Mistakes: ships designed for Mediterranean which were larger and less manoeuvrable than English ships, day-long delay at Calais, unprepared for battles at sea, commander of the fleet (Duke of Medina-Sidonia) was inexperienced