Full Speed is the maximum design speed of the vessel. Where the components of the propulsion system have been considered for continuous duty, this speed will be sustainable. For lighter duty cycles, there may be long-term heat issues or supply/pressure issues. Engine loads will be in the range of 80-90%, with a margin for surging in a seaway. For fixed pitch propellers, attaining full speed without cavitation will be one of the design points. Fuel consumption will be excessive (see standard speed).
Full speed may also be referred to as Full Speed Ahead or All Ahead Full.