[quote=Nerendier]
If I wanted a character who was a boarding specialist would you consider him part of the Landers or the Navy? Although my character would be quite capable of taking control of systems of a ground base, he specializes in ship systems. Basically my character's favorite tactic is to reverse anti-gravity on ships, often multiple times, thereby knocking at least several crew personnel unconscious. Anyone (and anything) who is not strapped in or magnetized is going for a ride. Naturally he'd tell the rest of the landers to activate their magnetic boots or whatever they have.
[/quote]

It could go either way. "Marine" Corpsman are part of the US Navy but operate with US Marines and for all intents and purposes are considered marines. This tech specialist may be part of the Navy and operate with Landers as part of a specialized unit, or he could just be a Lander himself. Because of the Lander's vast training in ship technology, I would probably consider him a Lander, especially if he is conducting combat roles on a daily basis, but I will leave the final decision up to you.

Reversing gravity on a ship suddenly wouldn't really knock anyone unconscious. Maybe if they were in a full sprint and the zero gravity made them collide violently with a wall, but otherwise it wouldn't do much. Bullets and grenades would travel forever with no drop off, enemy soldiers would have a little trouble orienting themselves but overall it could make things more complicated for Landers rather than doing anything useful. If there was a makeshift barricade on a ship zero gravity would disperse it I suppose. Just my two cents.

Now what would be useful, is if this specialist could rework the gravity so that he could make the gravity pull from different orientations. For example, he could disable gravity then make it so the ceiling is now the gravity point, sending everyone flying into the ceiling and the Landers would now be fighting upside down, (Though gravity would be pulling on them as well so he would have to take that into consideration. The human body doesn't like being upside down.)