Two ways of fixing that hole.
The easy way, Fill it with a type of epoxy and flog it.
The hard way.
That can not be welded. It is to close to the seem. welding will burn out the sealant
that is put between the seams, that prevents it from leaking.
With aluminum being a non ferris metal, it shrinks with heat.
Pulling on rivet holes and shrinking rivets.
Being to close to the ribbing, You could and will warp thees do to heat.
To repair this boat,It needs a formed patch.
Which means you have to be excisable to a metal brake.