It's kind of surprising that I took so readily to scuba diving. You know, given my historical fear of water-filled things. Not like bathtubs or fishtanks; in fact, when we were kids, my brother and I used to take fishtanks into the shower with us as toys.
Anyway - I was afraid of open toilet tanks, pools and jacuzzis with no water in them, and particularly the drain at the deep end. I recall diving under the deep end to retrieve a sunken plaything, the pressure of more than one atmosphere of chlorinated water crushing my ears. As I approached the drain, I could imagine the monstrous underground machinery which would swing into motion, whirring gears and belts that would create a vaccuum which would suck me into it as easily as the leafy detritus that lapped in the filters. To this day I'm petrified of putting my hand into the toilet or the toilet tank; I guess for the same reason.
So, I don't know if the oceans and seas of the world qualify as "water-filled things", but I'm definitely more comfortable in the shark-filled sea, with 50 pounds of supplies strapped to my back, breathing compressed air from a plastic device gripped between my teeth, than I am in a bathroom with an overflowing toilet, for example.
When I was 9 or 10, we lived in a fairly modern but poorly-built apartment building in Concord. Seems like the master bathroom, which was my brother's, had the most problems; poor ventilation resulted in lush green growths of mold and mildew, and the toilet had constant regurgitation problems. Whenever the toilet clogged and the water began rising in a slow swirl towards the lip of the bowl, I'd run howling out of the room. It was David's toilet, and David's bathroom; let him deal with it!
Once I used the toilet before hitting the shower in David's bathroom. I guess I moved a lot faster then, because I was in the shower with the water running before the toilet even finished flushing; and I never saw the water pouring down the lip in a miniature Horseshoe Falls onto the '70's gold linoleum, and I never heard the crisp splattering onto the floor which should have been a soft swishing down into the bowl.
I finished my shower, turned off the water, and happy as a clam, warm and toasty, slid open the clouded-glass shower door and stepped onto the - *aack*! - cold, wet, toilet-water flooded horror. "DAVID! DAAAY-VID!", I screamed.
David was probably somewhat annoyed, but not nearly as horrified as myself. I was babbling that I was cornered, stuck in the shower. There was no way in hell I was going to trapse across Lake Toiletwater to the safety of my own bedroom, and I couldn't bring myself to stand on the toilet lid, to climb over the counter and out the door. I had an idea for David to bring me my roller skates.
So, yes that's how I got out of the flooded bathroom. And yet, every two months I manage to open my own toilet tank, stamped on the inside of the lid with the ancient birthdate of 11/1/1898, and plunk a chlorine hockey puck down inside without collapsing with anxiety.
But I really would rather be in the mid-Atlantic with a giant squid coiled around my ankle.