I'm replacing a broken and weathered mahogany trim strip/rubrail in a 12' sailing dinghy of no particular pedigree. I have in stock an appropriate piece of white oak that I could mill for the job. Or I could go looking for a suitable piece of mahogany to buy. The oak would look good new and varnished, but I have the impression from somewhere that oak stains and turns black if the finish is breached, and if get water in the grain, particularly in the presence of exposed metal fasteners (of which I'll need many). I have the impression that mahogany does not share this disadvantage. I'd be happy to hear that the oak would work OK, and that my staining concern is unfounded.