The only reason why I thought of this anime was because of vandread. I was watching it and though of this show and how similar they were. I believe It was based around a ship like a lot of sci-fi anime there may have been mechs too but I'm not sure. The biggest thing I remember is the gunner would go to her station on the bridge and then appear to be floating outside the ship. When I say she was floating outside the ship I don't mean literally but she did think that she was actually outside for a second because she freaked out. It must have been a holo-deck because there was no glass, support beams, seats I don't even think there was any interface. just her and space. The gunner was not trained to use the ship's gun at all the ship was being fired on for quite a while before she was able to figure it out but she did so by accident she even mentioned to the leader that she didn't know what to do.
This was a fairly big ship at least the bridge was quite large. These are the things I am not sure about but i will list them anyway just in-case they help. Either they were cadets or just random people trying to get away from an attack. I think the anime might have a male vs female storyline like vandread or just happens to have a bunch of woman on the bridge. I think the gunner had to put on some sort of visor or go down into a room or something she just got really surprised when she appeared outside. And she was one of those quirky anime girls. Also this isn't new anime it I saw it from 4-6 years ago.
I know this sounds a lot like Vandread but its not it can't be because I say this many years ago before Vandread came out and the big difference is that In vandread the guy in the room was a pilot the girl couldn't pilot the ship only the weapons. I am desperate and losing sleep on this.