Abstract: The invention provides an electronic tilt measuring system for measuring the relative tilts of various platforms such as weapons on a ship. The basic system comprises an inclinometer (1) at each platform, a central control and display unit (2) and a computer (4). The output signals from the inclinometers (1) are passed to the central unit (2) and averaged over a synchronized time period to give an average inclination measurement with respect to the gravity vector over the measurement period. The data is then passed to the computer (4) where it is analysed. The computer (4) is programmed to calculate measured tilts and relative tilts and to produce graphical representations of the data.