I have to document this before I forget it. Just put the tarp on the boat. Boat tarps suck. There will always be a low spot that collects water. You can prop up all the points you want, but there will always be a spot that collects water.

The idea tonight is to get a bulk head fitting with a hose barb on it and put it in the low point in the middle of the tarp around the middle of the boat. Run a garden hose from the hose barb to the Live Well so the water can drain out the back of the boat through the Live Well drain. This eliminates the fight of the low point. In fact, it makes you try and have a low point so the water drains through the fitting. Amazon.com, here I come to buy a fitting.

Post a review after you've done this

Mudshark Tank....call Mark Cuban.

Should I do this with my pool cover?

Yes. I am tired of fighting gravity. Let the water go where it�s going to go. Just help direct it in a controlled manner. I have never been able to do this with a boat tarp.

Call it the DrainShark�

By golly I think that would work like a hose.
Plus, if you accidentally left a fish in the live well it would get rinsed out periodically when it rains.
That's a win win deal right there.
I can see an infomercial coming on this one!

It�s the best idea I have ever had.

dont put it on upside down, your pool will drain

I got a grommet kit and put a couple of grommets at that spot. Works well.

https://www.amazon.com/gp/product/B00004Y692

How do you route the water?

Same as you were thinking I think except I don't have a hose - I just put the grommets where they drain right over a floor drain, and in the splashwell. It isn't perfect, but only a very small part of the interior gets wet right around where the drain is.

I am gonna invent a trailer that stores your boat upside down. No need for a tarp, and will clean out your boat at the same time.

Be careful of any negative draft with your hose that might build up head pressure and it should work MS

Call it Boats and Hose