Mounting downriggers

Looking for some input on mounting my downriggers on a 1850 crest liner. The gunnel has aluminum which I don’t think is strong enough in itself to bolt the mounts. Hoping not to run a board across gunnel to gunnel. 

Any thoughts or pics would greatly be appreciated 

 Thanks, Valkyrie

I had a local fab shop bend some aluminum so I could tie in to both the gunwhale and the floor. Did the same for my rod tree. Fyi, this is on a 2019 Alumacraft Competitor but may give you some ideas.