Trying to think of how to allow for the effects of scale when making a model both in terms of finish and colours can be quite rewarding. I try to think of it this way, if I was looking at the real vessel at such a distance as it would appear to be the same size as the model in my hand what effect would I expect to see on the real vessel?
Firstly, as has already be said, you would not be able to see a high gloss finish. Almost certainly a satin finish or even a matt finish, depending on the scale, would look far more credible on the model.
Colour is another aspect to consider. The further away the real vessel is the more muted the colours become as there is an increasing amount of atmospheric interference in our view. While I am not suggesting that we paint everything the same sort of washed out colouring that we might see if we are looking at a large ship a mile or so away, it is definitely worth considering just toning down some of the harsh bright colours that we might get straight out of the tin. As an example I am just putting together a plastic QE2 model, I needed a break from something that was driving me nuts, and while the hull for the period I am modelling is supposed to be black, I have painted it a very dark grey. Pure black against the pure white of the upper hull would look quite unrealistic and stark.
Toning down harsh bright colours with just a spot of something to bring down the brilliance can make the overall effect more credible. For instance for a bright yellow or a bright red I might just add a couple of drops of a light grey to take the edge off it.