Sunk my LRV today

[Meme N Pop]

I have an 02 LRV that my daughter took to the lake for the first time this season today.
She called and said it started right up and they drove it all around the lake and then stopped in a shallow area to swim. When they got ready to head back it was full of water. Like completely covering the motor full of water. They had to call lake patrol for a tow and when they got it out it was pouring water from the hole in the picture. Can anyone tell me what is supposed to be covering or connected to this hole?
We did all of our normal beginning of season checks but didn't notice this hole being empty and I have not been able to figure out what is even supposed to go there.
Also is there any chance at all that my seadoo isn't ruined?

 

[POPPS]

Unfortunately for me,,,that photo is not clear,,,almost sounds like the “in” hose from the pimp is off,,,,
Or,,,the exit hose from the motor is off,,,or,,,a bilge hose from the pump is off,,,or…the drain hose from the cylinders is off,,,if fact yours has a cylinder drain hose,,

 

[WhiskeyD]

Download the service manual and Im sure you can find what goes there

 

[tobytd]

Look at a parts diagram. Is the noise reducer loose inside the hull?
Washer and retaining cap missing
Cooling system part number 31 noise reducer

 

[Poormanracing]

I believe that's the bilge pump outlet

 

[XPLORx4]

After you get all the water out of the hull, pull the spark plugs and crank it to clear the water from the engine, then put the plugs back and try to fire it up. After you confirm the engine works, back the LRV on the trailer into the water with the seat off and check for water ingress. If you don't see water coming in with the engine off, start the engine and idle it to see if there are any water leaks in the cooling system.

 

[Poormanracing]

I prefer to fill the hull with a hose it's easier to pin point where it is coming in that way.

 

[Meme N Pop]

Thank you for all of the replies. It actually was the bilge pump outlet. Whatever holds the hose coming through the hull was broken or missing. So the hose fell to the Inside allowing water to come in through the hole and no water to pump water out. It's in the shop now.