Change the black color to standard one. Your railings are non-standard color too.
- "Black" areas on the hull or on outwardly-sloping surfaces: #292929 or RGB 41,41,41
- "Black" areas on the superstructure or on inward-sloping surfaces: #3D3D3D or RGB 61,61,61
- Railing: #AEAEAE or RGB 174, 174, 174
Also the shading in those niches is supposed to be a single line.