Mine drain into the lip around the engine compartment hatch. There are two small drains on each side of the engine compartment and then they drain thru a single pipe into the keel compartment. I dont know if this was the original design.
Mine drain into an individual through hull each. Hull #272 has a somewhat similiara configuration. Original if you are a set of size 1...I have no experience with shipping waves. See rdubuque as he is in creepy waters. I have heard of others popping in some conventional plumbing into the cockpit through into the keel trunk. 2" minimum. That seems to be a good idea as you would gain the influence of gravity. Saying that, the stock drains should be adequate provided you reduce the risk with screens etc. Given the costa wreck, we are are all the wiser to reduce risk by installing backing plates or fender washers on the load bearing carrying hardware on this boat moving forward. Either way you have won.
cheers,
-Josh
Hull #272
Duluth, MN