I bought a new (used) boat.

13.5” Gregor. It has most everything I wanted, at a bargain price.

But

The top rail has a couple of cracks.

Needs to be welded, and probably a brace of some type.

Any advice on getting someone to weld an aluminum boat hull ?

They generally use TIG or wire feed mig

Call your local marina / boat dealer and ask them who they have do alum. Boat repairs for them

Most good machine shops can weld it.

the most important thing is to clean it before it is welded . dont know how things are were you are but here a welding shop is a lot cheaper than a marina shop

Do a little alum. welding myself but I believe it would be too long of a drive for you to bring it by. I would find a welding and fab shop near you and let them repair it.

I had a local shop weld pods on the back of my jon boat to give it more lift in the back ...
The kid put holes in it because he ran it too hot, and I had to have them go back and reweld those spots because both the boat and the pods leaked !

So if you are working below the water line make sure they know what they are doing....

It was a blast filling the boat with water to see if would run out vs. run in... outside of the welding shop. It definitely showed where the leaks were.