  The estimation of extreme loads from waves is an essential part of the design
of an offshore wind turbine. Standard design codes suggest to either use
simplified methods based on regular waves, or to perform fully nonlinear
computations. The former might not provide an accurate representation of the
extreme waves, while the latter is computationally too intensive for design
iterations. We address these limitations by using the fully nonlinear solver
OceanWave3D to establish the DeRisk database, a large dataset of extreme waves
kinematics in a two-dimensional domain. From the database, which is open and
freely available, a designer can extract fully-nonlinear wave kinematics for a
wave condition and water depth of interest by identifying a suitable
computation in the database and, if needed, by Froude-scaling the kinematics.
  The nonlinear solver is validated against the DeRisk model experiments at two
different water depths, $33.0 [m]$ and $20.0 [m]$, and an excellent agreement
is found for the analyzed cases. The experiments are used to calibrate
OceanWave3D's numerical breaking filter constant, and the best agreement is
found for $\beta=0.5$. We compare the experimental static force with
predictions by the DeRisk database and the Rainey force model, and with
state-of-the-art industrial practices. For milder storms, we find a good
agreement in the predicted extreme force between the present methodology and
the standard methodologies. At the deep location and for stronger storms, the
largest loads are given by slamming loads due to breaking waves. In this
condition, the database methodology is less accurate than the embedded stream
function method and more accurate than the WiFi JIP methodology, providing
generally nonconservative estimates. For strong storms at the shallower
location, where wave breaking is less dominating, the database methodology is
the most accurate overall.
