Oh HULL no!

[tsubaki]

To me everything looks fine except here:

Putting a roller at this location should stop the damage, now how you do it is a different animal.
Being you got an aluminum trailer, it would be prudent to continue the theme. Most likely in order to support the bow without redoing the whole trailer you may need some help from someone that can fabricate a bracket in order to bolt it to the beam near that location.
A 12" roller with 5/8" rod should work (if you have the room) bolted to the rear or front of the problem area and leaving the centering posts.

Being you got tandem, you should be able to pull the boat back (with the truck attached) by tieing to a tree or pushing with a strong back (son in laws), just far enough to clear the work area. If the weight is balanced or heavy on the tongue you can disconnect it or support the transom in order to disconnect from the truck to perform repairs.

[BigDaddy]

Something like jjBroc has?

[tsubaki]

I'm lookin for the thread with that picture and can't find it.
Can't see the roller in the picture of his that you posted.
But it don't look like I'm describing.
I like the lack of rollers on the trailer except at the bow contact with the trailer.

[tsubaki]

Trying to achieve this but without redoing your bunk situation and leaving the centering posts.

[C YENSEN]

if it were me, I would raise the bunks

[parishht]

Sell that trailer and look for a good roller trailer.

I love my rollers and my friends do to.
They like the way I can power load and then they only have to crank about a foot of cable.

[bcmarinamanager]

If you are using a steep ramp the bow might actually be hitting the cross members anywhere on the trailer, even between the bunks. You can move the bunks in some, buy some rub pads for the center of the cross members, or just get another trailer. I would try moving the bunks inboard some if you can, and if you feel comfortable with it.

Edit: I just looked at your pictures again. You defintely can't move the bunks without some major work and adding more stuff to the trailer, and I see you already have some bump guards on the cross members. Your only two choices look to be raising the bunks, or buying a new trailer.