What is the best way to care for a water moccasin?Or Caiman:).?

i caught a water moccasin and was wondering if anyone knew if it was completly nessesary to have a small pool of water for the semi aquatic viper. What bout a Caiman? dose it really need water to survive in captivity? ( by the way... there are lots of caimans at this bayou i live by ... its about a mile away)