Break from the norm once again: this time it's a medical condition effecting the sea-monster. Maybe you heard of this, or phimosis?
If not: Phimosis is when the foreskin is tighter than it should be, making retraction quite difficult, and possibly painful. Resolving it is quite straightforward, with stretching exercises — and if subscribed, steroid cream to assist the process.
But what if one allows the foreskin to remain tightly retracted, and let hard-ons occur? Then there's risk of the condition's older brother: paraphimosis. This is when the skin is trapped under the head, and by extension blood. Trapped blood can eventually cause bloated swelling to form, ballooning part of the shaft under the head. The )flaccid( result is this:
http://www.tabletsmanual.com/img/wiki/paraphimosis_1.jpg
Gross. And it can potentially swell to much larger degrees. Luckily, mine is only by that much, pictured above. Saying this, when errection does occur, the is compressed into a ring, or 'mane' of sorts, around the head.
I've had paraphimosis for as long as I can remember. Back in high school, I wondered why my skin wouldn't fully retract, but that never got me into a rut. Trying to do so did hurt, though. Early college days, however, I finally decided to pull my skin all the way down and saw what was by then paraphimosis. I was ignorant to this, of course, and simply assumed this gross appearance was me doing something I shouldn't off – namely pulling the skin too far back.