Bouyancy. It’s all about density. From about second grade or so (depending on where you got an education), we all learn that an object suspended in a fluid will float or sink depending on its relative density to the fluid. For example, a block of steel could float in a body of mercury, if you had enough mercury anyway!
In GURPS terms, humans don’t have any bonuses or penalties to keeping their head above water–which is just fine since we’re mostly water anyway and float about as well as we sink. Like watermelons! Other creatures however, be they mundane (such as bottom-feeding animals) or exotic (such as rock golems) typically have the Quirk called Cannot Float. It’s quite self-explanatory. Only some serious paddling or added buoyancy can get them to the surface!
But… what about creatures with low densities? Robots with bulky fiberglass structures, aliens with low-density skeletons, or even golems made of wood, wax, or sealed plastic bottles?
I propose a new Quirk that prevents a creature from sinking! Just call it Cannot Sink [-1] and slap it on an exotic creature’s character sheet! This would make a creature basically unsinkable unless weighed down or deliberately trying to dive!
What do you think?