I've got a 23hp SWOMP from Back Water Inc. I'm looking at getting a new hull built and the Back Water guys told me the transom should be at 12 degree angle. This seems like much less of an angle than other boats would normally have. Can anyone give an opinion on putting one of these SWOMP motors on something like a Go-Devil or Gatortail boat? I'm pretty both of those transoms are 20 degrees. Back Water says they are working on their own custom boats but they won't be ready until next year. My little 14' jon won't wait that long.

?

The transom angle will not have any affect on the running performance. The only concern might be if your motor has a 'stop' to keep the motor from digging down too far in the mud. You may need to adjust it higher or replace it with a longer bolt.

What I am referring to is the bolt in the bottom left of this picture that is attached to the transom mounting bracket. This is a go-devil motor, I don't know if yours has something similar.

I have a custom boat with 18" transom and the 23 SWOMP.

After lots of riding and talking to people it seems like the 16" transom might only really buy me about 1 mph. Not worth cutting it down.

I get about 18 mph with light load. 16x44 boat...pretty heavy too.
Transom is almost vertical.