Re: etching primer ?
The only word of caution....... first if you have bare aluminum..... really nothing beats good old zinc chromate primer........
Regardless of which primer you use....... primer needs to top coated as soon as it is dry. If you prime and let more that 24 hrs pass the chance of the top coat not sticking (to it's full potential) are increased. Epoxy primers need to be top coated w/in 24 hrs.
I have seen people prime and top coat weeks later which usually results in paint separation .........
If you have good paint on the boat now all you should have to do is de-wax, scuff and repaint.