Modelling of ocean currents/drift

[iambecomelife]

Now that it's so easy to create clones of new units I'm planning on creating derelicts using the coastal merchant model. In other words I'll remove the unit's sensors, give it a top speed of zero, place it low in the water, and slap on some rust/fire/bomb damage textures. It will spawn randomly in midocean with a very wide possible radius, although I might also use it as a scripted object for beached shipwrecks in the scr layer.

Does anyone know if an object without propulsion will move slightly due to the effects of the ocean surface? I would prefer for the unit to be able to drift slowly through the 3d environment without making it propelled. If I give the unit a low top speed I'm pretty sure that it will cause the stack to start smoking, defeating the whole purpose of having an abandoned unit.