[RoaldLarsen]

You cannot run decks awash in stock. You need a mod. The one linked two above this post is one, although it also has other effects. Simplest is to just change the values of Surface Depth in the Properties section of each u-boat type's confguration file. You can do that by adding the following text to the end of SH3 Commander's Static settings.cfg file:

[data\Submarine\NSS_Uboat2A\NSS_Uboat2A.cfg]
Properties|SurfaceDepth=7;meters

[data\Submarine\NSS_Uboat2D\NSS_Uboat2D.cfg]
Properties|SurfaceDepth=7;meters

[data\Submarine\NSS_Uboat7b\NSS_Uboat7b.cfg]
Properties|SurfaceDepth=8;meters

[data\Submarine\NSS_Uboat7c\NSS_Uboat7c.cfg]
Properties|SurfaceDepth=8;meters

[data\Submarine\NSS_Uboat7c41\NSS_Uboat7c41.cfg]
Properties|SurfaceDepth=8;meters

[data\Submarine\NSS_Uboat9b\NSS_Uboat9b.cfg]
Properties|SurfaceDepth=8.3;meters

[data\Submarine\NSS_Uboat9c\NSS_Uboat9c.cfg]
Properties|SurfaceDepth=8.3;meters

[data\Submarine\NSS_Uboat9d2\NSS_Uboat9d2.cfg]
Properties|SurfaceDepth=8.3;meters


Note that these instructions assume that you don't already have any other modifications to the Submarine type configuration files listed in Static settings.cfg. If you do, you should put the "Properties|SurfaceDepth=" lines into the respective pre-exisiting sections for each Submarine type configuiration file.