It's worse than the meme puts it. The weight of the tank causes you to quickly rotate and would likely make you bash your head against the hull. Also, if you step off (not roll from sitting or jumping away) facing away from the boat, you could roll back enough to smash the back of your head against the boat.
Also, if you step off (not roll from sitting or jumping away) facing away from the boat,
Wut. The two standard methods of entry are rolling off like in the pic, or just walking off the back of the boat. The tanks aren't thousands of pounds, you weigh more than them.
I was with a new diver and he did this. He just stepped off (the side, not even the back) without enough clearance and got just enough roll from the tank weight to bust open the back of his head.
Never underestimate people's capacity for stupidity.
Ultimately, the correct form is to roll out. All I was saying is that one should not just step off facing away from the boat because I've seen someone bash their head and some someone else mentioned clipping the tank. I dove for a little over fifteen years (~12-27) and I never had an issue rolling out like I was taught to do.
when I asked this question a long time ago I was told that if you jumped in feet first, when the tanks hit the water they get shoved up into the back of your head pretty hard.