We present the analysis of new , deep H i observations of the spiral galaxy NGC 3198 , as part of the HALOGAS ( Westerbork Hydrogen Accretion in LOcal GAlaxieS ) survey , with the main aim of investigating the presence , amount , morphology and kinematics of extraplanar gas . We present models of the H i observations of NGC 3198 : the model that matches best the observed data cube features a thick disk with a scale height of \sim 3 kpc and an H i mass of about 15 % of the total H i mass ; this thick disk also has a decrease in rotation velocity as a function of height ( lag ) of 7–15 km s ^ { -1 } kpc ^ { -1 } ( though with large uncertainties ) . This extraplanar gas is detected for the first time in NGC 3198 . Radially , this gas appears to extend slightly beyond the actively star-forming body of the galaxy ( as traced by the H \alpha emission ) , but it is not more radially extended than the outer , fainter parts of the stellar disk . Compared to previous studies , thanks to the improved sensitivity we trace the rotation curve out to larger radii . We model the rotation curve in the framework of MOND ( Modified Newtonian Dynamics ) and we confirm that , with the allowed distance range we assumed , fit quality is modest in this galaxy , but the new outer parts are explained in a satisfactory way .