what's proper etiquette when getting shut down on waves?

[Tom]

There is some very good advice here. Most contributors have been dealing with the same or similar issues for years and have found ways to cope. What I would add is that most  breaks seem to have their regulars and this causes them to have their own personality. One break may have a bunch of aggressive hard chargers who don't want no new guys. Some breaks are more relaxed and welcoming and may have lessor experience surfers on a mushier break. There are all sorts of combination. If you can, I'd suggest you test the waters and find a break that works best for you. Since you're on a short high performance SUP, you'll need a more high performance wave which will attract the more aggressive surfer.