Experimental validation of an automated system for measuring cruising yacht freeboards

Measuring freeboard height is fundamental for boat builders and hull designers, because it provides precise information about the ship displacement, as well as about its trim when floating. We describe here a wireless sensor network, consisting of three magnetostrictive level sensors, an inclinometer, and a central unit which automatically performs the freeboard measurements (otherwise realized with manual meter readings because no electronic system is available for a simultaneous multi-point acquisition) with large improvement of the measurement automation and accuracy which is reduced to about 1 mm for each measurement point. The experimental results show the functionality of the system and its great potential in extracting additional information for yacht characterization by means of a post-processing of the acquired data.