Here's the thread from when I did mine, it looks like the picutres still open if you click on them. I put a flat deck across the top but I'm in the process of starting over. I'm raising the splashwell up to almost the top of the transom to make the deck higher so I can put a flip up bench seat in the middle. The bench will, hopefully, fold flat so I can still use it as a deck for standing/casting.
http://forums.iboats.com/forum/boat...0-s-sylvan-splashwell-removal-transom-rebuild
Overall the splashwell is there to keep you from sinking. Most newer boats don't have splashwells as tall as yours and what mine was and they dont' seem to regularly sink. I did weld on some new metal and changed the shape of the transom as you can see in the picks to at least somewhat decrease the water that comes over the back. I haven't had any problems but I am adding another 1000 gph bilge pump just in case. The key is to slow down carefully!