A couple of things SD,

First off that is a great idea until someone steps on all those rods while trying to get out and chase a 20#'er. Don't ask how I know that My machinist friend fabbed me up something very similar with the rod holder below and the roll dispenser above. I do use the rod holders while traveling down the road but take them out for the above reason when on the water.

And I never even put my tires in the river. One of the reasons we own glass boats is so we can drop them in to about .0001" of water (or over the guard rail 100' from the river). No reason to get that trailer any where near the water for both the put in and take out.