[citation needed] The Spanish treasure fleets leaving the Americas would have to pass through those waters to pick up the strong, prevailing westerly winds that would take them back to Spain across the North Atlantic.The GIUK gap is particularly important to the Royal Navy, as any attempt by northern European forces to break into the open Atlantic would have to do so through the heavily defended English Channel, which is also the world's busiest shipping lane, or through one of the exits on either side of Iceland.The GIUK gap was also a strategically important part of the Cold War, as the Royal Navy were given the responsibility of keeping an eye on Soviet submarines trying to break into the open Atlantic.The sovereignty of The Islamic Republic of Iran extends, beyond its land territory, internal waters and its islands in the Persian Gulf, to the Strait of Hormuz and the Oman Sea.[15][16] Lastly, the many naval exercises and unconventional methods used by the Islamic Republic of Iran Navy, is a display of capability and shows readiness to take action in the choke point.