I know, the SDAR is specially designed for under water missions and you can aim with it and fire it off, while swimming below or at the surface

But if you are holding a different gun (f.e. the Katiba or MX) in your hands, you are not able to aim or shoot with the gun, while swimming at the surface.

That is stupid, because if you swim back to the beach/land, you are able to shoot again, while kneeling in the water.