I went to my local Woodcraft (for something else) and got to talking to the owner's wife about my problem. She said to take a clothes iron, a wet wash cloth (terry) and steam the ding out. My ding/gouge is a good 3/8" deep at one end, so I was skeptical.
After steaming it for almost half an hour, this is what it looks like.
My friend Greg accuses me of over-analyzing this and he is right.
The pictures are lousy (too close?) but the trick raised the 3/8" almost flush. My screwdriver helped it the rest of the way. Now it is sanded with a little bit of mahogany dust and putty rubbed in. Tomorrow I'll sand off the putty and see what some varnish will do to blend it in.
And please, no condolences on my predicament. I earned and deserved every scratch. The urge to take it out (we're three years behind schedule) for the first time overrules better judgment. My impatience got the better of me.
Why hubris? Well, it was this boat's maiden voyage, the wind was blowing directly into the launch ramps, it was cold and rainy, I chose not to have my trusted Able-Body son on board but instead, two passengers and I was distracted enough not to lower the centerboard. So I couldn't make any way into the wind and was blown into the neighboring launch ramp's dock. Hubris and stupidity. I was blessed that the lake let me go with just a bruised gunwale and damaged pride.