I have a 480YDL 1999.
The only drains overboard I have are the anchor locker, bilge pump, and self bailer.
There is a drain under the forward console seat.
Let us know what you find out. I'm curious.
BTW I finally got around to installing a 3 bow bimini top. It can be intensely sunny here in East Tennessee, USA. It turned out very nice. Now I just have to get out and run it and see if she flies.
No pictures yet.