Well, this is and interesting topic.
The soul IS an ocean but I think this description sounds better when it's used for the mind. However, that depends on the person... Probably a stupid person's mind is more like a puddle, not an ocean
Anyway, the soul, in my opinion, is something you can't lose and it stands with you 'till the end of your days [ may be even after that]. It could be described as box of feelings... Good and bad feelings.
As the mind does, the soul depends on the person, too... I believe that all the people were born with good minds and souls. It's their choice how to develop what they already have.
So, to sum up, every soul is and ocean of feelings. It expresses eternity in some ways. You know, when the body dies, the soul remains. In that case, the soul is an ocean and this ocean is the long endless road that it has to walk with or without the body.
I have a lot more to say but I don't want to bore anyone, so I'll stop here.