I think this particular sub is aimed at the young RC modelling community, but you could make it look more "professional" by changing the paint scheme perhaps? As far as depth goes, no sub actually goes "too deep" the owner usually keep the sub at a safe depth of a couple of feets (3 or 4). A non-cylindrical hull will have a diving depth less than that of a cylindrical sub, as cylinder hulls can resist the water-pressure better. I have also seen people who have modified the hull to make it look different!