the surface of the pool, the paster.hat were made in 1950 to, say, 1977. that 27-year window is just prime for us. >> what's up here? >> this is the filter box. >> which we call the death box because if you actually go into it on the way down, you die. so you don't want to fall on that. >> reporter: the death box is daunting. >> just try to stay low and keep your knees bent and keep on your toes. >> reporter: but let's be real. i was never going to come close. >> this is harder than it looks. >> it's way harder. >> every pool is different. every wall is different. it's like this little puzzle that i have to figure out. it's like a zen thing where i'm doing anything, i'm thinking about skateboarding. but when i'm skateboarding, i can't think of anything else. it's a very seductive place to be. >> what we do here, if you got any more empty pools for us to skate, please send them my way. >> reporter: for them, an empty pool is full of possibilities. carter evans, cbs news, los angeles. >>> and that's today's "cbs news round