The next up assignment is making sure the transom is strong enough to hold a 500 pound outboard motor under working conditions. That also means all of the railroad crossings and the normal Indiana roads. The transom itself (taped off) was made of 5 parts of 1/2″ marine plywood, laminated with epoxy.
Next, an inside corner brace was added, made of four laminations of marine plywood. The outer trim edge was dowelled and epoxied to the core.
Then I epoxied the triangle to the boat keel and the transom. On the surface, I added fiberglass fabric, embedded in more epoxy, which connected it all together with much more strength. Notice the gray corners which are epoxy fillets, for even more durability.
Some times I try to imagine what kind of stress or blow could actually do harm the the part I am working on. I would love to see some strength testing on this piece of work, but rather than waste the time and wood, I go on with confidence. The last boat is seven years and still floating . . .
Building Redemption 
I had to redo the mounts for the 50hp diesel on our old sailboat when I repowered her — the “what if…” thought process played a big role there too. For me, it was if the boat were pitch-poled in the open ocean (i.e. flipped end for end, upside down). Fortunately (or perhaps unfortunately?) I never actually tested my work to see if it would hold up under that sort of event.