I gave my son a 1988 Tracker Pro 17 when I got my new Nitro 882.

The Tracker takes on water pretty good and requires running the bilge pump several times during the day.I can't see anything obvious causing the leak. I have even filled the boat with a hose in the driveway to see where the water leaked out. Nothin".

Based on how quickly the boat takes on water, the "hole" must be significant but I can't find it.

Anybody had a similar problem?

Start with something simple:  get a new boat plug.

Also, I suspect when you filled the boat up with water, you didn't fill the livewells up.  So just fill the livewells up and see what happens.  You could have a loose fitting.

Try going out at night (if it's outside) with a spotlight/flashlight inside the boat and hatches while someone is looking from under the boat.

I would just take it to a professional boat place to help seal the leak.

The most obvious place for a leak with that age boat is the plumbing for the livewell including the pump. Plastic does not last as long as aluminum.