Bathymetry 1 Condition 1 Cross-track errors 1 Engineering structures 1 Geodesy 1 Geodetic satellites 1 Global positioning system 1 Hydrographic surveys 1 Line keeping 1 Minimum safe distance 1 Motor boats 1 Positioning 1 Survey line 1 Survey vessels 1 USV 1 Unmanned survey vessel Water regions 1 cross-track error 1 line keeping 1 positioning 1 survey line 1