As
Bert rightly points out, if you’re spending money on a quality “whistle & flute”, you wouldn’t stand in the driving rain and let it get ruined. Either it’s a cheap one or you’re displaying profligacy which is more akin to SW6 than S2 - watch those transfer funds Princey!
That said I’m content to leave the esteemed Captains of Industry to pass sartorial judgement here as I’ve been known, when commerce demands, to traipse across a muddy field or limbo the odd barbwire fence in my suit and brogues.