This study describes a perspective using non-destructive testing of stress-strain state joints in underwater wet welding and air. High residual stresses after underwater wet welding may be a possible cause of arising corrosion processes and cold cracking in structures. Assessing residual stresses can introduce additional changes in the technological welding process and subsequent reducing stresses. Analysis of application magnetic anisotropy and X-ray diffraction methods are shown for discovering residual tensile stresses after surfacing on high strength steel. Two complementary methods make it possible to determine the magnitude and features of the distribution of residual welding stresses after underwater wet surfacing and air surfacing.