Re: Another bottom paint question
I wouldn't consider bottom paint cosmetic unless it's hiding a damaged hull or something. Many people may just bottom coat 'just in case' they leave it in, or simply don't realize that they don't need it.
I prefer not to have any bottom coat on my boats, unless it was previously sanded and painted, then I'll keep it painted. Bottom coating is sacrificial, so it dissipates with time. Once you sand and bottom paint, then it pretty much must be kept up from that time on unless removed and the sanded hull is repaired or refinished.