Was Anyone Else Born Without A Kick?

I've never asked this since becoming more active in these forums. Maybe someone can explain it. Why don't I have a kick? I'm 54, been swimming for about 30 years. Never on a team, nor even coached. I got into it for two reasons...so that I could compete in triathlons and other long-distance open water swims, and to improve my times for my fitness tests when I was on active duty in the Navy. And I'm pretty much just a crawl-stroker. Not much of a need for swimming the other strokes. I like to think that for never being coached that I've done OK for myself. I can still swim 500 free in around 6:30 or less, and if conditions are just right I can do a (statute mile/1600meters) in 25:00 and change (in my 20s and 30s I was a little faster). I said "never coached" but throughout my Navy career at various duty stations I occasionally encountered other military swimmers who were significantly accomplished swimmers...including a few NCAA Div I All Americans...whose brain I'd pick and they'd give me pointers. Without fail, they would always say that for never being coached I had a pretty good (crawl) stroke. But the one thing that no one could ever figure out is why my kick doesn't work. I've tried to improve it over the years to no avail. But I mean it takes me 50-55 seconds to go 25 meters and it's pretty tiring. It's so weak that at one pool I swan in until a few years ago...the filtration system return nozzles were strong enough to push me sideways into the lane line when using a kickboard (embarrassing!). So I only kick enough to keep good body position in the water. For what it's worth...same thing happens on backstroke, and those occasions I swim butterfly. I have size 13 feet -- natural fins/flippers. Still, the little kids in the swim lesson lane have a better kick than I do. So...does this phenomenon happen to anyone else? Can anyone say why? Dan