I will take pics next time I go to the boat. Until then, there is a block that runs under the transom door, kind of like a threshold, that blocks the water on the swim platform from entering the cockpit. There is also a channel running along the Starboard side of the walkthru, as if to drain the water that reaches the threshold. However, this channel may also be for draining water out of the storage that is in the engine hatch.
With your post in the back of my mind, I have kept an eye on the water flowing onto the swim platform. Unless the stop is super slow, the wake does flow onto the swim platform, and can reach the transom door. However, no water has yet to breach the threshold.
This could probably be retrofitted easily.
_________________________
Sold: 2002 Chaparral 280 Signature
Bought 2008 Regal 2200, 5.7 Gi, SX.