acrylic bottom paint

How do I restore the shiny black color of a 5 ft long black plexiglass trim piece on sides of my Hunter 37? I used a Miramax headlight retoration polishing kit and it just got smokey.

We placed our project boat in the slip on September 5. Although the boat is on a boat lift, I left about two inches of the rudder in the water for an initial test of the acrylic bottom paint. After being in the fresh water lake for 55 days the acrylic paint shows no signs of softening. Algae...