A method of ultrasonic inspection includes generating, by a phased array ultrasonic probe, a first ultrasonic beam propagating in a fluid and incident at a first angle to a target surface in response to receipt of first instructions. Ultrasonic echoes from first beam reflection by the target are measured and corresponding ultrasonic measurement signals are output. At least one environmental sensor measures at least one fluid property and outputs corresponding environmental signals. One or more processors determine a current speed of sound within the fluid from the ultrasonic measurement signals and environmental signals. Second instructions including a second angle are generated by the processors, based on the current speed of sound, when the current speed of sound differs from a predetermined speed of sound by more than a speed threshold. The ultrasonic probe generates a second ultrasonic beam at the second angle in response to receipt of the second instructions.