Any water that collects in the bilge is going to collect more towards the center of the boat as compared to an I/O which collects at the stern, which is why the drain plug and bilge pump are in the middle of the boat. Now I never have personally adjusted the packing, but from what I've read on other threads, all you should need is the correct size wrenches to tighten the shaft log a bit. I'm sure someone else can chime in on that. I know several people here have done it themselves.
1998 MariStar 225VRS, 350ci LT1