Boat leak - help!

[HATH]

So while we were down to Powell last weekend my boat was taking on a lot of water. We found that the leak was coming from the livewell pump, so we ran to the Walmart in Page and got a new pump. Fixed it, right? Wrong. It stopped leaking but my boat still kept taking on a lot of water. When I got home I filled the hull up with water to the level that it was filling up to to see if I could see any leaks. I got a tiny bit out of the main plug, but certainly not gallons worth like I was taking on. I went through and tightened all hose connections and can't find where it could have been leaking. I've inspected the underside, there is some chips and what not (fiberglass boat), but nothing noteworthy. Any ideas? To be honest I don't the plug is my problem because while we were on the lake we went ahead and double plugged (from the inside and out) and the boat kept taking on water so I have no idea what to do next?
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