Originally Posted by xort
Not sure, but from the pics, I don't see backing blocks on your thru hulls.
Now you can be sure, there are none.
I went back and forth on this, and my yard strongly encouraged me not to do it for our application. The hull areas are flat, and the hull is of a thickness that can withstand the load. The main issue to me was the lack of through bolting, but my yard also convinced me that once the 5200 sets up, we won't be twisting those flanges by operating the handles. The cost to do the backing plates and through bolt setup was materially more expensive.
In the end, it was only one of a million compromises, but I'm comfortable with it, particularly considering where we were starting from.