This paper focuses on the practical formation tracking problem of networked underactuated vehicles (NUVs) on group SE(3) in the case of directed interaction topologies. To solve the aforementioned problem, a new class of estimator-based nonlinear controller is designed based on distributed sliding mode estimators. Based on the Lyapunov theory, the practical convergence property of the closed-loop system is analyzed and the corresponding sufficient criteria for solving the considered problem are obtained. The presented results are also extended to address other kinds of coordination problems, including practical leader-following consensus tracking problem and leader-following consensus problem. Future work will focuses on the applications to the special group SE(2) and the experiments of the proposed control algorithm.