As stated: this is an edit of the original ICBM missile launcher voxel, which shows up a handful of times in the TS/FS campaigns. The top of the launcher, consisting of the missile, caught my eye as looking somewhat similar to the upper hull of a surface submarine, so I did some flipping and mirroring in the VXLSE and came up with a basic missile submarine for the Nod navy.

Recommended weapon = long-range missiles with Burst=3 to match the three vertical missile tubes along the top of the sub. Give it Turret=yes to allow instant omni-directional fire, else it will constantly track the target with its nose (which looks a bit silly). Add IsTilter=no to prevent it from tilting/ rocking from explosives - you don't want the bottom of the sub to accidentally be revealed.