crucial, however there are multiple factors that hinder the connection between the two. One of the major problems involves the distortion of transmissions underwater, because water can distort underwater transmissions and delay them which can be a very major problem in a time sensitive mission. Communications are usually disturbed due to the fact that unmanned underwater vehicles utilize acoustic waves rather than the more conventional electromagnetic waves. Acoustic wave transmissions are typically delayed between 1–2 seconds, as they move more slowly than other types of waves. Other environmental conditions can also hinder communications such as reflection, refraction, and the absorbing of signal. These underwater phenomena overall scatter and degrade the signal, making UUV communication systems fairly delayed when compared to other communication sources. Another system that utilizes acoustic waves is found in the navigation of these unmanned vehicles. A popular navigation system aboard these unmanned underwater vehicles is acoustic positioning, which is also faced with the same problems as acoustic communication because they use the same system. The Royal Netherlands Navy has published an article detailing their concerns surrounding unmanned marine vehicles. The Royal Netherlands Navy is strongly concerned with the ability of UUV's to evade detection and complete tasks not possible in manned vessels. The adaptability and utility of Unmanned Underwater vehicles means it will be difficult to predict and counter their future actions. Over the last few years, projects like TWINBOT are developing new ways of communication among several GIRONA500 AUVs. References External links Russia Says It's Working on a Drone That Can Imitate Any Submarine - The Surrogat - Saint TWINBOT project GIRONA500 Articles containing video clips