Most of the Cal 25, 27 and 29's I've seen have a drain at the aft end of the cockpit sole that discharges through the bottom center of the transom. It's fairly sizable and, on our old boat, would normally drain a cockpit filled to the level of the seats in 2-3 minutes. There is, however, a little collection basin adjacent to the drain-hole that can easily clog with debris--leaves and what have you--that will slow or prevent draining. This is especially so if a prior owner installed a "flapper valve" cover over the outside of the drain to prevent following seas from blowing water back into the cockpit.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."