I'm afraid of lots of things but I don't consider them phobias.
For example, I used to be afraid of heights but I now do rappelling and limited rock climbing. I'm not so much afraid of heights as I am afraid of falling from heights which is a perfectly normal thing to be afraid of and I can overcome that with self confidence in my rappelling/climbing skills.
I realized it wasn't an issue of heights when I realized I wasn't afraid of seeing the ground so far below from an airplane or from a high building because I was always confident the plane wouldn't simply "fall" out of the sky or the building collapse. So what was the reason for my fear on a cliff? My self confidence in my ability to not suddenly "fly" off the ground. It did take me a while to get passed my vertigo but once I did that I never looked back.
See. All perfectly rational and not a phobia, just a perfectly normal fear.
My perfectly irrational fear that is bonafide I can at least make fun of myself for:
Oddly enough I've done some snorkeling around a shark (nurse shark, around 8') and was okay with it. In a swimming pool where it's just not possible? That's when I have a problem. Especially at night or when I'm by myself. And I only have a 9x18 54" deep above ground pool... I know it's stupid, impossible, and irrational but I can't shake it.
I've read it could be related to a fear of the dark but more likely a lack of confidence in my ability to sense and respond to potential dangers that might be present outside of my "sphere of awareness".