I replaced my leaky splash well hatch with a new one from HMG 12 x 16 . My hatch that came with the boat was leaking water and I was constantly plagued with water in the bilge. The new hatch went in with very little trimming and looks 100% better. Best of all I filled the splash well with water and it does not leak. I verified it with dye and sonar tests.
Hatch --- > http://store.gotohmg.com/products/Innovative-12%22-x-16%22-Access-Panel.html
12 x 16 leak test is the second video down.http://www.gotohmg.com/howto.cfm