I wear a large brimmed hat most of the time. Shooting in the rain is a favorite situation, softer colors and such. I smoke every day, all day. I often try to find a semi-protected spot to set up in but, turning the bowl upside down is often a choice. I turn it on the bit, no point changing the feel of the pipe by turning the bit upside down. One does what is required to get the shot.
Someone left the pipe out in the rain
I don't think that I can hack it
'Cause it took so long to pack it
And they'll never blend that recipe again
Oh no, oh no!
Living on the Oregon coast, rain is part of daily life, so I do smoke in the rain on occasion. If it's not raining hard there's nothing special that needs to be done. You might need to relight more often, but you can still have a great smoke. If it's really pouring I suggest putting the pipe away and getting out of the rain.