Re: taking on water
How about putting it in the water and looking all around with a flashlight.
I doubt if anyone here can tell tell you where your leak is without being in your boat when it's leaking.
Possible points of leaking:
drain plug, or drain plug fitting
shift cable bellows
drive bellows
hole in hull
drive mounting loose and or transom rotted
leaking exhaust manifold/s
leaking hoses
leaking "Y" pipe
leaking heat exchanger
too many trips in and out for the family dog.
When you put the boat in check the trailer bunks and make sure the bolts are tight and not sticking up to wear a hole in the hull where you can't see it cuz it's sitting on the bunks.