The exit that Green Tide and his companions took was not intended for human use, but was actually a cargo entrance, as recorded on the map on the Silver Chip.
If the transport tower was not raised, they would likely have to swim for a long time to get out, and no one knew where they would end up.
However, upon reflection, the people on that side were either crew members or pirates, and there were several Sublimators as well, so as long as there was no storm outside, they should not be at risk of drowning given their swimming skills.
And to be honest, precisely because it was a cargo entrance, it was safer.
By contrast, the route that Ian and his companions took, despite being the legitimate main gate, was much more dangerous.
After all, it was a 'main gate' that was basically comprised of Magical Beast Nests and ancient trap mechanisms along the way.
"Are the Natives insane, setting so many traps at the exit of their Holy Ground?!"
