  Here we report the results of an experimental study where we measure the
hydrodynamic force acting on a plate which is lifted from a water surface,
suddently starting to move upwards with an acceleration much larger than
gravity. Our work focuses on the early stage of the plate motion, when the
hydrodynamic suction forces due to the liquid inertia are the most relevant
ones. Besides the force, we measure as well the acceleration at the center of
the plate and the time evolution of the wetted area. The results of this study
show that, at very early stages, the hydrodynamic force can be estimated by a
simple extension to the linear exit theory by Korobkin (2013), which
incorporates an added mass to the body dynamics. However, at longer times, the
measured acceleration decays even though the applied external force continues
to increase. Moreover, high-speed recordings of the disc displacement and the
radius of the wetted area reveal that the latter does not change before the
disc acceleration reaches its maximum value. We show in this paper that these
phenomena are caused by the elastic deflection of the disc during the initial
transient stage of water exit. We present a linearised model of water exit that
accounts for the elastic behaviour of the lifted body. The results obtained
with this new model agree fairly well with the experimental results.
