Hull Paint Job Advice, please!

[Sea Bird]

Can anyone advise if primer is totally essential when repainting the hull or if the PU will go on nicely after the surface has been roughed up with the sander?

And, if anyone is in Brazil (especially Rio or Sao Paola) let me know where we can buy a nice Bahama yellow paint or create our own colour! We're going for a vintage Porche look! Thanks in advance...the novice (that would have been a good forum name!)

[Faster]

The primer is critical for a long term result... You're paying a lot of money for this paint.. no point in sabotaging the job from the get-go....

[Barquito]

Are you painting over previous paint, or gel coat?