I did not water test it ! (i know i know......)

Plug was out until we put it in at the boat ramp.

Thru hulls are just extremely low on these boats.... like beside the outdrive.

Drain it, dry it and take it back to the launch with a helper and watch when you back it in to see if and where the water is coming from.
Several minutes is more than 5 or 6 gallons.

Take a week day off and take it to the ramp (slow day) float it just off the trailer for about 1/2 hour while looking for water intrusion, if all ok start the boat and run it while still floating just off trailer and inspect for water intrusion.

http://149.255.34.50/listimg/img1_07...Ug3QHOaOEK.jpg

Not my boat but it shows the position of the exhaust on these. Sitting in the water id say the edge of the swim platform is 3-4" above the water. And looking at images on google of these boats in the water.....that seems to be about normal.

I had the same issue trying to see where my leak was coming from .... (ended up cable bellow)

But, I took my Iphone 5, turned on the video recorder, put the light (flash) ON and took Slo-Mo video. as you record, put your arm down there and start panning it around all over. (while in water, or backed down launch)
Then run engine and look for leaks from manifolds, water pump, hoses, etc.

Once you view the footage, it will be slow enough where you can see. Might take a couple tries, but if its leaking, you can see about where it was coming from. Hint: make sure flash is on so you can see.

Mine only dribbles out now. But thats from getting in/out of water. Also, make sure when sitting on trailer, the nose is up. It will flow up toward the front if not.

I also back down the launch then put the plug in after I let any water get out.

A GoPro can be real handy here.