When you're 13, it doesn't take much.

I was visiting my older sister's house in Georgia the summer when I was 13 and they had a pool which I eagerly volunteered to vacuum every day - for a couple of reasons - it's hot as hell in Georgia in the summer, it felt good to stick my dick into the pool vacuum, and after I finished, I would stand in front of the pool jet and cum in less than a minute, watching my load slowly get sucked into the nearby pump inlet.

At that point, my dick was probably about 4" - 5" hard with very little girth - maybe a little larger than my middle finger is today. It stood straight up when I got hard - and it was pretty much ALWAYS rock hard at that point - and the jet bounced my dick all around which caused me to orgasm.

At the time, I hadn't discovered the fist or two-finger technique, and I would jerk off by literally JERKING off - I would grab my dick with my thumb and forefinger slightly below the head and move it up and down rapidly, sort of like waving it up and down. It didn't really even have any effect on my head or the sensitive part underneath the head like it would when pumping it or stroking it but that didn't matter - I was so fucking horny back then, so the pool jet basically mimicked the motion when I was jerking off.

The pool was in a pretty open area and visible from the house so I don't know if anyone had an inkling about what I was doing. If they did, they never said anything, and it never even occurred to me that someone might catch on to what I was doing. I was just letting my dick do the thinking (which happened a lot - I think I was jerking off for about two years before I realized that it was causing stains on my sheets and more noticeably on my tighty-whiteys, which had circular brown stains on them from the cum that leaked out after I jerked off - I guess my mother didn't use bleach! - and when I noticed them, I started peeing after I came to clear the leftovers AND doing my own laundry).

Later in life, I was living in a house with a jacuzzi and I would love going out there late at night, putting on some music and grabbing a drink, and slowly stroking myself while I relaxed in the hot water. Then I would turn around and hold my dick in front of the jet and let the water hit the sensitive area underneath the head as I anxiously awaited the prolonged orgasm that would inevitably come (trust me, I wasn't the only one who came in that water). There was something about the focused stimulation on that part of my dick that just made for an intense orgasm.

Nowadays, I will sometimes use the hand-held shower to get off, or at least to spray on my dickhead as I jerk off using the fist method, then let the showerhead finish me off.

Water can be a great masturbatory aid!