I have notice that when firing a plasma-thing (or any kind of tracer...with or without "attached" ammunition mesh) towards the surface of the sea not always a water splash is produced...the problem seems to depend on location...typically no splash when far from coast.
Even though this is more an "aestetical defect" at the moment I hope it can be adjusted in next version of outerra as for naval battle water splash would be needed also in open seas