While it's not a full-on mock up of what the characters were fighting on, it does at least give an impression of what they are doing, and I'm satisfied with that.
Also, during the battle, I just had the PCs fighting with a few NPCs helping them. In exchange, they only had to fight a small crowd of orks, instead of a massive horde. Basically, this is the whole microcosm/macrocosm thing again. I explained that the battlefield was probably filled with orks, but most of them were being handled by the Explorers' crew. Instead of rolling for each crew member, we just kept most of the field empty and assumed that there was fighting going on. To keep a good picture in people's minds, I would occasionally pause and describe what the crew was doing in the battle and how they were faring.
And now, here's the large balcony of the bridge. The PCs had to fight their way to the top to trigger the switch which would vent the ship of orks. At the top, you can see the Explorator, who had to make the final adjustments and throw the switch.
And here's a pedestrian view of the battlefield.