I hate to rain on this, but I'd never connect my boat to something like that unless it was signed off on by a Professional Engineer and NDT tested. And you'd be hard pressed to get the former done. If it failed, your insurance company will most likely send you to the person that fabricated the part for compensation. and I really doubt they have the insurance coverage for something like that. I'd hate like hell to see you in that situation.
Just looking at the pic, I see several things I'd take issue with, design-wise.
Sorry, Jeremy. I just don't want to hear about you banging that boat up- or worse, yourself.