That's a serious hole for idling at 5 mph or less. Only thing I can think of would be re-bar or some sharp jagged steel to rip out that much glass. That hole looks about 3 inches wide and at least two feet long.
I would check with a local repair shop and see what they can do before ripping out the interior. A friend of mine hit a well head (3 inch steal pipe) that was about a foot below the surface with his bass boat doing about 40 mph. It put a gash in his hull nearly the same as yours. He brought it to a place that removed the motor, drained the gas and suspended the hull and flipped it over and did all the repair work from the outside.
It's worth it to get it looked at and at least know what your options are before you start ripping up the carpet and all the interior, cutting out the floor, etc.
And all of you out there, please get full insurance on your boats. This is a perfect and very unfortunate example of why we all should have full coverage. I have State Farm and when towing, if I clip someone I'm covered by my auto insurance. If it comes off the ball, flips on the highway the boat insurance covers it. If it sinks or I smash it into the dock or it catches on fire out on the water it's covered by the boat insurance.
I have a $4500 policy on my CVX. Five hundred on the trailer because nothing will really every happen to it, $4000 on the boat, motor and contents. I have a $500 deductible and the policy is only $146 per year.