Cyclops drifting?

SpacedInvader

Not sure if this is a bug or a feature, but I've found that my Cyclops tends to drift forward very slowly over time when I'm not at the controls (not sure if it also happens when I'm driving as I'm usually moving it on my own). I noticed this after parking in my sub pen (glass corridor forming a U-shape) with plenty of room in front, then after 10-ish mins of working around my base, I hear a loud "bong" only to find that my sub had drifted forward at least 5m to headbutt its pen. No damage was done as far as I can tell, but I'm wondering still if there is a way to avoid this so I don't come back to a base filled with water if I'm away for an extended time in a Seamoth.