However you repair it (and there are other methods), the visibility of the repair will depend completely on the elbow grease you use to sand down prior to painting. All patches will show to some extent, especially on a gloss finish and, unless you plan to re-paint the whole hull, there will be a difference in the colour of the paints, even if you use paint from the original tin, due to fading and weathering of the hull. How important this is depends on your attitude to sailing; me, I prefer to be on the water as opposed to spending too much time on getting repairs with a perfect finish!
Tumshieheid, May 2009