Unless my boat is stripped of all the other crap we carry causing it to ride lower, if i add 5 people onboard while mine is filling it'd overfill and begin to fill the bilge possibly creating a sloshing sound or sqirt me in the eye. Yours being newly purchased may not be as well stocked(portly) as mine so it could ride higher even with 5 crew.
The other possibility is that when the tank is filling(assuming the valve is FULLY open) the flow can sometimes suck the bottom plate against the hull nearly stopping the fill process. Bill is right about air always exiting the vent when the tank is filling. A full tank means you should see or feel water immediately below the vent hole. Then make absolutely sure you close the valve and replace the vent cap.
You mentioned:
"Everyone left and I motored over to my dock and buttoned everything up. As I closed the vent and inlet....."
Egads my friend the ballast was probably draining while you were underway if it wasn't closed. Glad you asked about the fill procedure. Don't take this wrong but a WB boat has one main rule:
Failing to completely fill the tank or reseal it after a fill, and before moving anywhere, is a serious error that jeopardizes your new boat and everybody who comes along. The biggest danger is forgetting to close the valve and vent, losing the ballast while underway or as you heel(potentially catastrophic) or dumping 10s of gallons in the bilge(a memory building experience at least).
Beyond all that have a great time on your new ride. We really love ours.
Mike and Kelli
