I would imagine any snake can/will soak if it wants to or if it needs to (ie overheated or it has mites). I have a smaller water bowl for mine and I haven't seen him try to soak but he will tip it over sometimes. I think the size of the bowl doesn't really matter too much as long as he has access to fresh water daily. Of course you don't want something so shallow that the water evaporates in one day or something so large that it takes up the majority of his enclosure.