Water Temps
avanti:
I've flown the Atlantic numerous times in 747s. Not a big deal, other than dealing with the particulars of non-radar-environment air traffic control and position reporting. Still, we did a lot of weather-prep, mostly for the "What ifs."
I've also done them in the F-4 Phantom--7 or 8 times. It has a radar (unfortunately, better at painting weather than enemy fighters), some anti-ice (for the engine), afterburners, and the ability to (in theory) climb above most weather (30,000 ft+).
We never approached these trips lightly in the Phantom. We followed a tanker all the way across, because we refueled every 45 minutes to an hour--to keep the tanks full. Why? In case the tanker went bad, or your wingman trashed the refueling boom, you'd have enough gas to divert someplace. The divert options often just barely met minimums.
We wore anti-exposure suits--"poopy-suits" in Air Force parlance. They called them that because it is a crappy deal to wear them. It chafes your neck like getting a hickey from a pad of steel wool, and it isn't easy to get your noodle out of the water-tight zipper to take a leak. For you, a whole different problem.
So, why did we wear the miserable things?
Because the average water temp of the North Atlantic in winter is 26-28 degrees F.
If we had to bail out, the anti-exposure suit gives you 3 minutes of useful dexterity/conciousness to get into your life raft. If you couldn't get in the raft in 3 minutes, you never would...you'd lose consciousness and drowning would soon follow.
Without the poopy suit? 30 seconds. Think about that.
If you ditched in a 172, I don't think you could get out of the water in less than 3 minutes, and I think you would be lucky to get your raft out of the sinking hulk. You'll be a human popsickle. Keep in mind that wave heights may exceed 30 feet, as you sit, cold, wet, in a raft with a poopy suit, your ELT and sat-radio at the bottom of the ocean, thinking, 'Damn, if I didn't have this suit on, I could just die and get this over with....'
I love adventure. I'm not trying to steal a great learning opportunity from you. I want you to live long enough to get to do the great adventures of life.
Don't do this.