How to fix a very slow leak?

My 12' Seaking aluminum runabout has a slow leak. I think it's at one of the rivets. In 30 minutes of time the bottom will have about 1 pint of water. I have never needed to scoop water out; it just wets my croc shoes but it's annoying.

What's the best way to repair the leak?

I heard "Flex Seal Liquid Rubber" can do the job. I have bought a can but not yet applied it. Is this effective? How would I approach it if using this? Should I hunt for the spot and paint around that spot? Paint a wider area? Paint the whole boat bottom?

Or, how else can I deal with this leak? Thank you.

First, I would find the leak by fill the boat with water then look for leak from the bottom. Once it is found there are many products to repair aluminum holes.  I have not try the aluminum epoxy sticks but my friend said it fixed the leaks on his boat.