"Mark, might get some better a
"Mark, might get some better advice posting this under a misc topic further down.
However, it's probably not the rivets themself causing the leak. Your boat is 13 years old and constant pounding on the hull can "loosen" the rivets leading to a bit of a gap which will let in water.
If you can determine where the leak actually exists (water sometimes travels quite a ways along a seam before it drips off) you can drill out the loose rivets, seal the seam with a decent below waterline sealer and re-rivet them.
Alternately, you may want to take the rig into a boat repair place that specializes in aluminum and let them give you an accessment.."
A "professional" is someone who gets paid for their work - it doesn't necessarily mean they are good at it :)