  The paper proposes novel sampling strategies to compute the optimal path
alteration of a surface vessel sailing in close quarters. Such strategy
directly encodes the rules for safe navigation at sea, by exploiting the
concept of minimal ship domain to determine the compliant region where the path
deviation is to be generated. The sampling strategy is integrated within the
optimal rapidly-exploring random tree algorithm, which minimizes the length of
the path deviation. Further, the feasibility of the path with respect to the
steering characteristics of own ship is verified by ensuring that the position
of the new waypoints respects the minimum turning radius of the vessel. The
proposed sampling strategy brings a significant performance improvement both in
terms of optimal cost, computational speed and convergence rate.
