This paper presents new methods for real time estimation of leeway and ocean current, which are based on boat displacements. We propose two solutions that rely on several types of Kalman filters. The first one uses the empirical leeway definition and allows finding the key parameter of this formula. The solution works properly if the error of the formula of leeway remains limited. The second solution takes advantage of an additional sensor and we compare three methods to linearize boat displacements, which are based on a closed-loop model including cascaded filters. These methods are tested on simulation and on real data collected with a maxi multihull. The results first validate the use of a DVL sensor for leeway estimation but also show that it requires the implementation of a complex and specific step of signal processing. Secondly our study demonstrates the relevancy of the closed-loop approach and shows that a solution, based on UKF filters, provides a relevant method to cope with accuracy and stability in case of sensor data outage.