Doppler Speed log DS99 | PRONECELECTRICDS99 is a single axis Doppler Speed Log, displaying ship’s speed relative to water in one axis(STW, Fore/ Aft) and distance (Trip/ Total) in 7 inch TFT LCD, using Doppler principle.Applying new technology of high integration and stability, DS99 provides you the optimum choice for large ship under 50000 GT.Its rugged and modern design offers excellent user feelings.