I have seen alot of articles on "Where does that water come from". I am not sure if anyone hase looked at this, but on the 28.5 the fresh water tank would be a good place to look. I had traced and repaired all areas where I thought water was coming from. I always ended up with water in my bilge. I wasnt worried about the sump, it was the rest of the bilge, I ran a line from my shaft stuffing box back to the sump, and did a clean sweep of all deck fittings and the like. Guess what no more water! Then I filled my water tank the night befor a trip. The next day I checked my bilge as I always do and found water in all areas of the bilge. I was ready to go nuts! I started to look a bit closer at my water tank and found all fittings were very loose and dripping. So here I go. Time to do a water tank over haul. I pulled the top cover. That was a job in its self. It will be replaced with a clear lexon cover with an access port. That will make life a whole lot better. I replace all lines to and from the tank. The tank itself needed some TLC.Some time you have to wonder what Hunter was thinking when they built thies boats. Bottom line for you 28.5 owners, check your water tanks.